FOUS11 KWBC 230858
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
358 AM EST Fri Jan 23 2026

Valid 12Z Fri Jan 23 2026 - 12Z Mon Jan 26 2026


...Major winter storm to bring the potential for crippling icing,=20 significant sleet, and heavy snow from the Southern Plains through=20
the Southeast and up the Atlantic Coast into New England...

Forecast remains largely on track with only minor changes compared
to the previous cycle, with typical uncertainties surrounding the=20
depth and northern push of the mid-level warm nose. While this=20
uncertainty is rather minor from a synoptic scale, local forecasts=20
can still be drastically impacted by this feature. The event will=20
begin this morning across the Southern Plains and expand towards
the MS VLY tonight. The driver of this winter storm is an=20
impressive overlap of intensifying synoptic ascent with increasing=20 subtropical moisture.

The synoptic pattern becomes favorable today in response to the=20
evolution of multiple shortwaves rotating through an amplifying=20
trough across the eastern CONUS. A closed 500mb low off the Baja=20
Peninsula will begin to open and shear to the east, at the same=20
time dual shortwaves dig out of Saskatchewan/Alberta and into the=20
Northern Plains. As the northern shortwaves dive south and the Baja
low ejects east, the interaction of these features will lead to=20
increasing mid-level divergence overlapping pronounced height falls
to produce rich deep layer lift. The northern shortwave has=20
trended a tad slower with overnight guidance and allows for more
ridging out ahead of this system, helping shift the mid-level warm
nose farther north. Regardless, the impressive ascent will be on=20
top of an arctic cold front that will be sagging southward into the
Southern Plains and eventually work its way southeast to the Gulf=20
and Atlantic coasts by Saturday. This overlapping ascent will=20
materialize atop a moistening column as subtropical moisture=20
downstream of the Baja low streams northeast reflected by IVT that=20
reaches above the 97th percentile according to NAEFS, in a broad=20
swath from Texas to the Carolinas, with above the record (CFSR at=20
00Z) climatology by Sunday evening in the east.

This increasing moisture will result in a large swath of
precipitation expanding from the Southern Plains today, to the=20
MS VLY and TN VLY Saturday, into the Carolinas and Mid- Atlantic=20
by Sunday, and finally reaching the Northeast Sunday night. This is
a very large and impactful system across a huge portion of this=20
country. While impacts will be considerable in many areas (aided by
extreme cold), the icing (and sleet) and snow will be most=20
impressive across two distinct areas.

Freezing Rain and Sleet:
Arguably the most lasting impact associated with this winter storm
could be from heavy accumulating freezing rain and sleet stretching
from the Southern Plains, Mid- South, Tennessee Valley, and=20
southern Mid-Atlantic. This is due to very cold low-level arctic=20
air being reinforced by the strong high over the north-central U.S.
(and enhanced by pronounced mid-level confluence over the Great=20
Lakes and New England) and a warm nose aloft (at around 750mb per=20
cross section model soundings) melting snow as it falls through the
column before refreezing just before or at the surface,and in some
places this re-freezing layer is above the 90th percentile in=20
terms of depth, suggesting some locations will experience=20
exceptional sleet accumulations.=20

The greatest freezing rain amounts and impacts are currently=20
forecast across northeast TX through northern MS as favorable=20
thermal profiles linger for over 24 hours beginning Friday night.=20
WPC 72-hour probabilities for >0.5" of freezing rain are high >70%=20
across southern AR/northern LA into parts of northern MS. Here,=20
ice accretion could be crippling and exceed 0.75-1.00", (WPC=20
probabilities 40-50% for 1" of ice) which would almost certainly=20
lead to widespread long-lasting damage to infrastructure, including
power outages and tree damage. Major sleet accumulations are also=20
likely just north of the freezing rain area stretching from=20
southern OK/north TX through central AR and into the Mid- South,=20
with more than a few inches of sleet possible. The consistency of=20
the guidance in both placement and amounts for this area are=20
resulting in high confidence in an extreme event, leading to long-=20
lasting impacts both to travel and infrastructure due to the=20
bitterly cold airmass expected to linger into next week over the=20
region.

Heavy icing is also expected farther east into the southern=20
Appalachians and southern Mid-Atlantic. The setup across the=20
southern Mid- Atlantic down as far south as northern GA and areas=20
just inland from the coasts of the Carolinas is an extreme case of=20
CAD with a 1040mb high situated over the Interior Northeast on=20
Saturday night. While regional soundings indicate there may be
considerable sleet in this area as well, especially across southern
VA into northern NC, these CADs are notorious for their effective dry/isallobaric flow, enhanced by precipitation, leading to dry
wet-bulb advection offsetting the latent heat of freezing during
freezing rain. With such an impressive high in place at
precipitation onset, this will likely result in considerable
accumulations of sleet and freezing rain here, too, with WPC
probabilities indicating a moderate-to-high risk (60-80%) of at=20
least 0.5", highest across the Piedmont and northern GA. The=20
guidance has trended just a bit colder this afternoon, but=20
significant icing is also possible as far north as Richmond, VA and
towards southern MD.

Heavy Snow:
North of the mixed precipitation area and closely tied to both a
favorable LFQ of a zonally oriented 180kt upper jet and strong
700mb fgen, snow is the primary precipitation type stretching from
the southern High Plains of east-central NM and the southern
Rockies through the Plains, Mid-Mississippi Valley, Ohio Valley,
Mid-Atlantic, and reaching the Northeast by Sunday evening (with
additional expansion beyond this forecast period).=20

Favorable upslope flow as the strong arctic high pressure noses=20
southward along the High Plains behind a strong cold front starts=20
on Friday across the southern Rockies, with light snow and even a=20
chance for freezing drizzle at onset across the central Plains=20
until the column fully saturates. Heavy snow is then forecast to=20
begin breaking out Friday night from the central/southern Plains=20
through the mid-Mississippi Valley and spanning much of the Ohio=20
Valley and parts of the Midwest on Saturday. Snowfall rates could=20
near 1"/hr as strong lift through WAA/fgen intersects with a=20
region where the DGZ is forecast to be extremely deep (SREF
probabilities above 70% for >100mb of depth). This would allow for
efficient formation of dendrites where ample lift can fully=20
moisture the column. While this depth is impressive, regional
forecast soundings indicate that the best ascent may lie below this
DGZ in many areas, and there is only modest indication of any
isothermal layer beneath the DGZ to maintain aggregates. Despite
this, efficient and fluffy SLRs are likely in this area, and with a
long duration event expected, WPC probabilities are moderate
(40-60% )for at least 12 inches from southeastern KS and
northeastern OK into southern MO, with widespread 4+ inches=20
extending all the way back into the TX Panhandle and lower MS VLY.
Trends have been more favorable for snow vs lately on D1 across
eastern OK and central AR as guidance depicts stronger mid-level
fgen and dynamic cooling aloft to keep the entire column below 0C.
00z HREF also depicts the potential for 1"/hr snowfall rates in
this region. Will monitor this for potential adjustments=20
downstream.

Farther east, some heavier snowfall is becoming more likely for
parts of the Ohio Valley, and into the Mid-Atlantic, and especially
Northeast. Here, pronounced WAA and accompanying 850-700mb fgen
will drive pronounced ascent into a rapidly moistening column
thanks to IVT above the 90th climatological percentile. As the
upper trough (interaction of the southern and northern streams)
deepens over the Plains, downstream ascent will maximize and a
period of impressive WAA snow with snowfall rates >1"/hr are
likely. As secondary low pressure develops offshore (in a Miller B
type evolution), banded structures within the WAA are likely to
translate northward from the Mid-Atlantic into New England, and
then may pivot and drift eastward Sunday night into Monday. Where
this occurs, the heaviest total snowfall accumulations are
probable, reflected by WPC probabilities that are already above 60%
for 12+ inches. While there is some uncertainty into how much=20
mixing will pivot northward, especially from Washington D.C.=20
through Long Island, the interior portions (NW of I-95 and into=20
southern New England which will remain cold as the secondary low=20
develops and tracks near the 40/70 Benchmark) will remain mostly=20
snow with above- climo SLRs leading to significant snowfall=20
accumulations. One other uncertainty that has creeped into the
forecast is a pesky dry slot moving into the Mid-Atlantic and
Northeast Sunday night. This could dry out the mid-level and
drastically cut both precipitation and SLRs. In fact, freezing
drizzle could develop early Monday morning from northern Va to
northern NJ in this scenario before stronger westerly flow picks=20
up on Monday. Many areas are expected to receive more than 12=20
inches from the Ohio Valley through the Mid- Atlantic and into the=20
Northeast before this system winds down in New England on Monday=20
/D4/.

Key Messages for this system are linked below (Key Message 2)


...Great Lakes...=20
Day 1...

Expansive mid-level low centered over the Hudson Bay will begin to
shear open and translate to the east today as a secondary=20
shortwave rotates through its base and atop the Great Lakes this
evening. Behind this impulse, shortwave ridging will amplify=20
across the area, bringing an end to the persistent CAA and=20
associated lake- induced ascent on D1.

The subsequent W/NW flow and accompanying CAA will lead to
impressive lake effect snow (LES) in the favored W/NW snow belts
D1, with some pivoting to more N/NW by early Saturday. The=20
heaviest snowfall is likely east of Lake Ontario D1 where WPC=20
probabilities indicate a moderate risk (50-70%) for at least 8
additional inches in the Tug Hill Plateau. Elsewhere, WPC=20
probabilities suggest a moderate risk (50-70%) for at least 6=20
additional inches across the northeastern U.P.

Additionally, as an arctic cold front pivots into the Northeast,=20
snow squalls along and behind this front are possible. For more=20
details on the snow squall threat in the Northeast through Friday,=20
please refer to our Key Messages (Key Messages 3) below.


Snell/Weiss






...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!6i-JszDvIoz4IkeeFVBNKHjZJfHF0Ybqz-c67ZQcVC-f7= lPz-fsyMDtCovzI6Va6oo9mesLuh66CAbzexuk2Xq7kUJc$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!6i-JszDvIoz4IkeeFVBNKHjZJfHF0Ybqz-c67ZQcVC-f7= lPz-fsyMDtCovzI6Va6oo9mesLuh66CAbzexuk2eCfbSq8$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_3.png__;!!DZ3fjg!6i-JszDvIoz4IkeeFVBNKHjZJfHF0Ybqz-c67ZQcVC-f7= lPz-fsyMDtCovzI6Va6oo9mesLuh66CAbzexuk2Uae-1TY$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 232057
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
357 PM EST Fri Jan 23 2026

Valid 00Z Sat Jan 24 2026 - 00Z Tue Jan 27 2026


...Major winter storm to bring the potential for crippling icing,=20 significant sleet, and heavy snow from the Southern Plains through=20
the Southeast and up the Atlantic Coast into New England...

Meteorological Overview...

A massive winter storm, set to produce a swath of heavy snow and=20
dangerous ice accumulations, has begun today as tropical East=20
Pacific moisture streams out ahead of the 500mb closed low near the
Baja Peninsula. This moisture plume is clashing with the coldest=20
air-mass of the season, entrenching itself over the Nation's=20
Heartland. The moisture transport is exceptional with an
integrated vapor transport (IVT) above the 97.5 climatological=20
percentile per ECMWF SATs. The rich moisture from the south will=20
accompany strong 850-700mb WAA that results in classic over-runing=20
along a developing area of 850-700mb FGEN atop the Southern Plains.
Meanwhile, the upper trough in the Southwest and an emerging=20
upper- level shortwave trough over the Dakotas will strengthen a=20
250mb jet streak over the east-central U.S., placing its thermally-
direct right-entrance region over the Southern Plains. This=20
synoptic- scale setup helps to enhance the mesoscale below,=20
fostering heavy bands of snow and even elevated instability above=20
the low-level sub-freezing layer over north TX on east into the=20
Mid-South tonight and into Saturday.

By Saturday, as the upper low near Baja approaches Texas, its=20
associated jet streak over Mexico will co-locate its divergent=20
left-exit region over the Mid-South and maximize upper-level ascent
over the region. The IVT in advance of the upper trough over=20
Mexico is both expansive and strong with >90th climatological=20
percentile IVT values originating south of Mexico and extending all
the way to the Southern Appalachians by Saturday afternoon. The=20
remarkable extent of the IVT and the slow progression of the Mexico
trough is why parts of the South and Mid-Atlantic are likely to=20
see snow, sleet, and freezing rain for over 24 hours and in some=20
cases approaching 48 hours. As arctic high pressure slides east, a=20
cold-air damming (CAD) signature will become well pronounced along=20
and east of the Appalachians as anomalous Pacific and Gulf moisture
arrives, leading to precipitation falling into the frigid air-mass
and supporting heavy snow, sleet, and freezing rain totals from=20
the southern Appalachians to the Mid-Atlantic.=20

Saturday night and into Sunday is where most changes in the
forecast have unfolded of late. It remains unclear just how strong
the emerging area of low pressure near the Gulf Coast will be and=20
how far north it gets. It is noteworthy that guidance is in good=20
agreement on 700mb Q-vector convergence over northern AL and the=20
southern Appalachians, but the GFS is a little farther south in=20
positioning while the ECMWF is a littler farther north and=20
stronger, resulting in the northern shifts over the last couple=20
days. What they do both agree on is by Sunday, a very pronounced=20
area of strong 700mb Q-vector convergence will unfold along the=20
Mid-Atlantic coast, prompting the development of a coastal low=20
along a strengthening coastal front. With the benefit of the 250mb
jet streak's divergent right-entrance region aloft and the=20
strengthening IVT (ECMWF SATs show >99.5 climatological percentile=20
values over the Southeast Sunday morning), an expansive=20
precipitation shield will span across the OH Valley, Mid-Atlantic,=20
and Northeast with excessive amounts of wintry precipitation=20
falling. While there remains some question on precipitation type,=20
the ECMWF EFI shows the QPF is >0.8 from the Southern Plains and=20
Mid-South to the Northeast, implying an unusually high amount of=20
QPF for this time of year will be at this winter storm's disposal=20
as it falls into a bitterly cold Arctic air-mass.=20

Heavy Snow/Sleet...

The latest forecast calls an astonishingly long swath (over 2,000=20
mile long in length) of >6" of snowfall that starts in the Sangre=20
De Cristo and Sacramento mountains of New Mexico all the way to=20
Downeast Maine. It is worth noting that the snowfall probabilities=20
being referenced will have snow and sleet. Focusing on the Plains=20
first, WPC probabilities sport high chances (>70%) for snowfall >8"
over central OK, southeast KS, southwest MO, and northwest AR.=20
There is another impressive swath of high chance probabilities=20

70%) for >8" of snow from southern IN and north-central KY to=20

eastern Maine. The Central Appalachians, interior Northeast, and=20
southern New England are likely to see the most snowfall with high=20
chances (>70%) for over a foot of snow in these areas. In fact, WPC probabilities show low-to-moderate chances (30-50%) for totals=20
over 18" in the Catskills, Berkshires, and eastern MA. Farther=20
south, the inclusion of sleet from NY and Long Island southward=20
along the I-95 corridor will likely cut into snowfall totals.=20 Climatologically speaking, areas west of I-95 where topography=20
increases are most likely to see more snow than sleet. This is=20
evident in the >8" for snow and sleet probabilities where they are=20
high (>70% chances) from northwest VA and north-central MD along=20
Parrs Ridge to the Lower Susquehanna Valley, but below 50% over=20
southern NJ, the MD eastern shore, and south of Fredericksburg, VA.
Still, the WSO shows >50% chances for a warning-level snowfall as=20
far south as central VA on east through the northern DelMarVa and=20
into southern NJ due to the strong 850-700mb FGEN Saturday night=20
and Sunday morning that fosters snowfall rates that could ranges
between 1-2"/hr. So while snowfall/sleet totals are not quite as=20
high as their neighbors to the north, the combination of snow,=20
sleet, and inclusion of some freezing rain still support=20
significant travel disruptions in these southern areas as well.=20

The WSSI shows widespread Major Impacts (considerable disruptions
to daily life: dangerous to impossible driving conditions,=20
widespread closures, and disruptions to infrastructure) from the TX
Panhandle on east to the Ozarks, through the OH Valley, and all the
way to New England. Every major market along the I-95 metropolitan
corridor (Washington D.C. to Boston and even as far north as
Portland, ME) are expecting major impacts due to snow. The=20
D.C/Baltimore area on north to Philly and NYC are likely to see=20
some inclusion of sleet, but it will still result in significant=20
impacts when accounting for heavy snowfall that is expected to
exceed warning criteria (5-6"). A reminder that bitterly cold=20
temperatures will follow in wake of this storm Monday and into the=20
middle of the week throughout the eastern U.S.. The snow/sleet=20
impacts will linger well into next week with rounds of re-freezing=20
that keeps surfaces icy and dangerous to both drive and walk on for
the foreseeable future. Those in the path of this storm should=20
make final preparations and put plans in place for significant=20
travel disruptions this weekend and into at least early next week.


Freezing Rain:

The most lasting and dangerous impact will come as a result of=20
significant to locally catastrophic ice accumulations due to=20
prolonged periods of freezing rain. Just like the swath of >6" of=20
snowfall, the areal coverage of high chances (>50%) in WPC's ice=20 probabilities exceeding one-quarter inch of ice accumulation is=20
both impressive and alarming. From east-central TX to southern AR,=20
northern LA, northern MS, the TN Valley, northern GA, the southern=20 Appalachians, and southern Mid-Atlantic, these regions are all=20
likely to experience anywhere from one-quarter to one-half inch of=20
ice. Widespread power outages and tree damage is likely in these=20
areas, especially from the Lower MS Valley, southern Appalachians,=20
and central NC where there are also high chances (>70%) for ice=20 accumulations over one-half inch. It is parts of northern AL,=20
northern MS, south-central TN, far northern GA, the southern=20
Appalachians, and the NC Piedmont that are of greatest concern.=20
WPC probabilities show low-to-moderate chances (20-40%) for ice=20 accumulations over 1 inch. These areas are likely to endure a=20
crippling ice storm that will take days, if not weeks, of clean up=20
in addition to extended power outages. Residents in these areas=20
should take final preparations now. Once the freezing rain starts,=20
dangerous travel will be common not only during the event, but in=20
the days in wake of the storm due to prolonged sub-freezing=20
temperatures that cause persistent re-freezing on all untreated=20
surfaces. The Key Messages for the Extreme Cold are linked below
(Key Message 1).

Farther east, freezing rain will reach southern VA, the DelMarVa
Peninsula, and as far north as southern NJ. The southern VA
Piedmont, including the Richmond metro area, have moderate chances
(40-60%) for over one-half inch of ice. The WSSI depicts Major=20
Impacts from Richmond on south along I-95 into NC, while Moderate=20
Impacts (hazardous travel conditions) are anticipated as far north=20
as the northern DelMarVa Peninsula and into the Lower Delaware=20
Valley. While most areas farther north towards the Lower Delaware=20
Valley and southern NJ should largely remain sleet, it may=20
transition to freezing rain for a brief time by Sunday evening. WPC probabilities show low-to-moderate chances (30-50%) for over one-=20
tench of an inch of ice accumulations Sunday evening.


Key Messages for this system are linked below (Key Message 2)


Mullinax



...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!8GUWGIKvjpbH7j06LCzf76dgj7wKmpMcynczXffJXXaY-= mNp6L2dr8o-PiAMPcRJ2YyFHPbCmPdKNKW5sTA1hXXuSxM$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!8GUWGIKvjpbH7j06LCzf76dgj7wKmpMcynczXffJXXaY-= mNp6L2dr8o-PiAMPcRJ2YyFHPbCmPdKNKW5sTA1nTFVkNQ$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_3.png__;!!DZ3fjg!8GUWGIKvjpbH7j06LCzf76dgj7wKmpMcynczXffJXXaY-= mNp6L2dr8o-PiAMPcRJ2YyFHPbCmPdKNKW5sTA1sbzsBKw$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 232103
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
403 PM EST Fri Jan 23 2026

Valid 00Z Sat Jan 24 2026 - 00Z Tue Jan 27 2026


...Major winter storm to bring the potential for crippling icing,=20 significant sleet, and heavy snow from the Southern Plains through=20
the Southeast and up the Atlantic Coast into New England...

Meteorological Overview...

A massive winter storm, set to produce a swath of heavy snow and=20
dangerous ice accumulations, has begun today as tropical East=20
Pacific moisture streams out ahead of the 500mb closed low near the
Baja Peninsula. This moisture plume is clashing with the coldest=20
air-mass of the season, entrenching itself over the Nation's=20
Heartland. The moisture transport is exceptional with an
integrated vapor transport (IVT) above the 97.5 climatological=20
percentile per ECMWF SATs. The rich moisture from the south will=20
accompany strong 850-700mb WAA that results in classic over-runing=20
along a developing area of 850-700mb FGEN atop the Southern Plains.
Meanwhile, the upper trough in the Southwest and an emerging=20
upper- level shortwave trough over the Dakotas will strengthen a=20
250mb jet streak over the east-central U.S., placing its thermally-
direct right-entrance region over the Southern Plains. This=20
synoptic- scale setup helps to enhance the mesoscale below,=20
fostering heavy bands of snow and even elevated instability above=20
the low-level sub-freezing layer over north TX on east into the=20
Mid-South tonight and into Saturday.

By Saturday, as the upper low near Baja approaches Texas, its=20
associated jet streak over Mexico will co-locate its divergent=20
left-exit region over the Mid-South and maximize upper-level ascent
over the region. The IVT in advance of the upper trough over=20
Mexico is both expansive and strong with >90th climatological=20
percentile IVT values originating south of Mexico and extending all
the way to the Southern Appalachians by Saturday afternoon. The=20
remarkable extent of the IVT and the slow progression of the Mexico
trough is why parts of the South and Mid-Atlantic are likely to=20
see snow, sleet, and freezing rain for over 24 hours and in some=20
cases approaching 48 hours. As arctic high pressure slides east, a=20
cold-air damming (CAD) signature will become well pronounced along=20
and east of the Appalachians as anomalous Pacific and Gulf moisture
arrives, leading to precipitation falling into the frigid air-mass
and supporting heavy snow, sleet, and freezing rain totals from=20
the southern Appalachians to the Mid-Atlantic.=20

Saturday night and into Sunday is where most changes in the
forecast have unfolded of late. It remains unclear just how strong
the emerging area of low pressure near the Gulf Coast will be and=20
how far north it gets. It is noteworthy that guidance is in good=20
agreement on 700mb Q-vector convergence over northern AL and the=20
southern Appalachians, but the GFS is a little farther south in=20
positioning while the ECMWF is a littler farther north and=20
stronger, resulting in the northern shifts over the last couple=20
days. What they do both agree on is by Sunday, a very pronounced=20
area of strong 700mb Q-vector convergence will unfold along the=20
Mid-Atlantic coast, prompting the development of a coastal low=20
along a strengthening coastal front. With the benefit of the 250mb
jet streak's divergent right-entrance region aloft and the=20
strengthening IVT (ECMWF SATs show >99.5 climatological percentile=20
values over the Southeast Sunday morning), an expansive=20
precipitation shield will span across the OH Valley, Mid-Atlantic,=20
and Northeast with excessive amounts of wintry precipitation=20
falling. While there remains some question on precipitation type,=20
the ECMWF EFI shows the QPF is >0.8 from the Southern Plains and=20
Mid-South to the Northeast, implying an unusually high amount of=20
QPF for this time of year will be at this winter storm's disposal=20
as it falls into a bitterly cold Arctic air-mass.=20

Heavy Snow/Sleet...

The latest forecast calls an astonishingly long swath (over 2,000=20
mile long in length) of >6" of snowfall that starts in the Sangre=20
De Cristo and Sacramento mountains of New Mexico all the way to=20
Downeast Maine. It is worth noting that the snowfall probabilities=20
being referenced will have snow and sleet. Focusing on the Plains=20
first, WPC probabilities sport high chances (>70%) for snowfall >8"
over central OK, southeast KS, southwest MO, and northwest AR.=20
There is another impressive swath of high chance probabilities=20

70%) for >8" of snow from southern IN and north-central KY to=20

eastern Maine. The Central Appalachians, interior Northeast, and=20
southern New England are likely to see the most snowfall with high=20
chances (>70%) for over a foot of snow in these areas. In fact, WPC probabilities show low-to-moderate chances (30-50%) for totals=20
over 18" in the Catskills, Berkshires, and eastern MA. Farther=20
south, the inclusion of sleet from NY and Long Island southward=20
along the I-95 corridor will likely cut into snowfall totals.=20 Climatologically speaking, areas west of I-95 where topography=20
increases are most likely to see more snow than sleet. This is=20
evident in the >8" for snow and sleet probabilities where they are=20
high (>70% chances) from northwest VA and north-central MD along=20
Parrs Ridge to the Lower Susquehanna Valley, but below 50% over=20
southern NJ, the MD eastern shore, and south of Fredericksburg, VA.
Still, the WSO shows >50% chances for a warning-level snowfall as=20
far south as central VA on east through the northern DelMarVa and=20
into southern NJ due to the strong 850-700mb FGEN Saturday night=20
and Sunday morning that fosters snowfall rates that could ranges
between 1-2"/hr. So while snowfall/sleet totals are not quite as=20
high as their neighbors to the north, the combination of snow,=20
sleet, and inclusion of some freezing rain still support=20
significant travel disruptions in these southern areas as well.=20

The WSSI shows widespread Major Impacts (considerable disruptions
to daily life: dangerous to impossible driving conditions,=20
widespread closures, and disruptions to infrastructure) from the TX
Panhandle on east to the Ozarks, through the OH Valley, and all the
way to New England. Every major market along the I-95 metropolitan
corridor (Washington D.C. to Boston and even as far north as
Portland, ME) are expecting major impacts due to snow. The=20
D.C/Baltimore area on north to Philly and NYC are likely to see=20
some inclusion of sleet, but it will still result in significant=20
impacts when accounting for heavy snowfall that is expected to
exceed warning criteria (5-6"). A reminder that bitterly cold=20
temperatures will follow in wake of this storm Monday and into the=20
middle of the week throughout the eastern U.S.. The snow/sleet=20
impacts will linger well into next week with rounds of re-freezing=20
that keeps surfaces icy and dangerous to both drive and walk on for
the foreseeable future. Those in the path of this storm should=20
make final preparations and put plans in place for significant=20
travel disruptions this weekend and into at least early next week.


Freezing Rain...

The most lasting and dangerous impact will come as a result of=20
significant to locally catastrophic ice accumulations due to=20
prolonged periods of freezing rain. Just like the swath of >6" of=20
snowfall, the areal coverage of high chances (>50%) in WPC's ice=20 probabilities exceeding one-quarter inch of ice accumulation is=20
both impressive and alarming. From east-central TX to southern AR,=20
northern LA, northern MS, the TN Valley, northern GA, the southern=20 Appalachians, and southern Mid-Atlantic, these regions are all=20
likely to experience anywhere from one-quarter to one-half inch of=20
ice. Widespread power outages and tree damage is likely in these=20
areas, especially from the Lower MS Valley, southern Appalachians,=20
and central NC where there are also high chances (>70%) for ice=20 accumulations over one-half inch.=20

It is parts of northern AL, northern MS, south-central TN, far=20
northern GA, the southern Appalachians, and the NC Piedmont that=20
are of greatest concern. WPC probabilities show low-to-moderate=20
chances (20-40%) for ice accumulations over 1 inch. These areas are
likely to endure a crippling ice storm that will take days, if not
weeks, of clean up in addition to extended power outages. This is=20 demonstrated in a rare Extreme Impact on the WSSI in parts of
northern MS, far southern TN, and the Southern Appalachians. The
WSSI Extreme criteria references the potential for "extensive and=20
widespread closures, extremely dangerous travel, and life-saving=20
actions may be needed." Residents in these all referenced regions=20
above should take final preparations now. Once the freezing rain=20
starts, dangerous travel will be common not only during the event,=20
but in the days in wake of the storm due to prolonged sub-freezing=20 temperatures that cause persistent re-freezing on all untreated=20
surfaces. The Key Messages for the Extreme Cold are linked below=20
(Key Message 1).

Farther east, freezing rain will reach southern VA, the DelMarVa
Peninsula, and as far north as southern NJ. The southern VA
Piedmont, including the Richmond metro area, have moderate chances
(40-60%) for over one-half inch of ice. The WSSI depicts Major=20
Impacts from Richmond on south along I-95 into NC, while Moderate=20
Impacts (hazardous travel conditions) are anticipated as far north=20
as the northern DelMarVa Peninsula and into the Lower Delaware=20
Valley. While most areas farther north towards the Lower Delaware=20
Valley and southern NJ should largely remain sleet, it may=20
transition to freezing rain for a brief time by Sunday evening. WPC probabilities show low-to-moderate chances (30-50%) for over one-=20
tench of an inch of ice accumulations Sunday evening.


Key Messages for this system are linked below (Key Message 2)


Mullinax




...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!8yFFARuqbgrlMXfpwPGS4uJRxeJOXQOZNw6H1nZpRTRha= rrS6kEy-awMjMQhdY74aJIFWgelYkKRsYNo7so9y2A1flY$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!8yFFARuqbgrlMXfpwPGS4uJRxeJOXQOZNw6H1nZpRTRha= rrS6kEy-awMjMQhdY74aJIFWgelYkKRsYNo7so9tj5CnIA$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_3.png__;!!DZ3fjg!8yFFARuqbgrlMXfpwPGS4uJRxeJOXQOZNw6H1nZpRTRha= rrS6kEy-awMjMQhdY74aJIFWgelYkKRsYNo7so9VdC50ig$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 240838
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
338 AM EST Sat Jan 24 2026

Valid 12Z Sat Jan 24 2026 - 12Z Tue Jan 27 2026


...Ongoing major winter storm to bring the potential for crippling
icing, significant sleet, and heavy snow from the Southern
Rockies/Plains through the Southeast and up the Atlantic Coast=20
into New England...

Meteorological Overview...

Forecast remains on track as a massive winter storm, set to=20
produce a swath of heavy snow and dangerous ice accumulations, has=20
begun across the southern Rockies and Plains as tropical East=20
Pacific moisture streams out ahead of the 500mb closed low near the
Baja Peninsula. This moisture plume is clashing with the coldest=20
air- mass of the season, entrenching itself over the Nation's=20
Heartland. The moisture transport is exceptional with an integrated
vapor transport (IVT) above the 97.5 climatological percentile per
ECMWF SATs. The rich moisture from the south will accompany strong
850-700mb WAA that results in classic over-runing along an area of
850-700mb FGEN stretching from atop the Southern Plains to the TN=20
VLY and southern Mid-Atlantic by tonight. Meanwhile, the upper=20
trough in the Southwest and an emerging upper- level shortwave=20
trough over the Dakotas will strengthen a zonally oriented 250mb=20
jet streak over the east- central U.S., placing its thermally-=20
direct right- entrance region over the Southern Plains and Mid-=20
South. This synoptic- scale setup helps to enhance the mesoscale=20
below, fostering heavy bands of snow and even elevated instability=20
above the low-level sub- freezing layer over north TX on east into=20
the Mid-South today.

As the upper low near Baja approaches Texas by tonight, its=20
associated jet streak over Mexico will co-locate its divergent=20
left-exit region over the southern Plains and Mid-South, maximizing=20
upper- level ascent over the region. The IVT in advance of the=20
upper trough over Mexico is both expansive and strong with >90th=20 climatological percentile IVT values originating south of Mexico=20
and extending all the way to the Southern Appalachians by Saturday=20 afternoon. The remarkable extent of the IVT and the slow=20
progression of the Mexico trough is why parts of the South and Mid-
Atlantic are likely to see snow, sleet, and freezing rain for over
24 hours and in some cases approaching 48 hours. As arctic high=20
pressure slides east, a substantial cold- air damming (CAD)=20
signature will become well pronounced along and east of the=20
Appalachians as anomalous Pacific and Gulf moisture arrives,=20
leading to precipitation falling into the frigid air-mass and=20
supporting heavy snow, sleet, and freezing rain totals from the=20
southern Appalachians to the Mid-Atlantic.=20

Saturday night (tonight) into Sunday is when this event truly=20
starts to peak in expansiveness and magnitude with wintry=20
precipitation continuously spanning from New Mexico to the=20
Northeast. Given the event is now well within the short range and=20
the synoptic pattern is locked into place, uncertainty now mostly=20
lies within the thermodynamics and both the depth as well as=20
latitudinal reach of the mid-level warm nose. Depending on which=20
CAM or global guidance you look at, this warm nose still has about=20
100 miles of uncertainty. This uncertainty is most notable where=20
WAA is strongest, throughout the Mid-Atlantic and into the=20
Northeast Saturday night into Sunday. Here, the NAM3k and RRFS=20
remain the farthest north and GFS/FV3 farthest south. WPC=20
preference tonight was in the middle, somewhere between the CMC-=20
Regional and NAM3k with how far north mixing would reach. What all=20
models do both agree on is by Sunday, a very pronounced area of=20
strong 700mb Q-vector convergence will unfold along the Mid-=20
Atlantic coast, prompting the development of a coastal low along a=20 strengthening coastal front. With the benefit of the 250mb jet=20
streak's divergent right- entrance region aloft and the=20
strengthening IVT (ECMWF SATs show >99.5 climatological percentile=20
values over the Southeast Sunday morning), an expansive=20
precipitation shield will span across the OH Valley, Mid-Atlantic,=20
and Northeast with excessive amounts of wintry precipitation=20
falling. While there remains some question on precipitation type,=20
NBM probabilities for >1.0" of QPF for the this event are greater=20
than 70% from the Southern Plains to southern New England, implying
a high amount of QPF that will be at this winter storm's disposal.


Heavy Snow/Sleet...

The latest forecast calls an astonishingly long swath (over 2,000=20
mile long in length) of >6" of snowfall that starts in the Sangre=20
De Cristo and Sacramento mountains of New Mexico all the way to=20
Downeast Maine. It is worth noting that the snowfall probabilities=20
being referenced will have snow and sleet and not include snowfall
already fallen prior to 12Z Saturday (this morning). Focusing on=20
the Plains first, WPC probabilities sport medium chances (50-70%%)
for snowfall >8" over the TX Panhandle, central OK, southern MO,
and northern AR. There is another impressive swath of high chance=20 probabilities (>70%) for >8" of snow from southern IL/IN and=20
north- central KY to eastern Maine. The Central Appalachians,=20
interior Northeast, and southern New England are likely to see the=20
most snowfall with high chances (>70%) for over a foot of snow in=20
these areas. In fact, WPC probabilities show low- to-moderate=20
chances (30-50%) for totals over 18" in the Catskills, Berkshires,=20
and eastern MA to the southern coast of ME. Farther south, the=20
inclusion of sleet from the LI sound southward along the I-95=20
corridor will likely cut into snowfall totals. Climatologically=20
speaking, areas west of I-95 where topography increases are most=20
likely to see more snow than sleet. This is evident in the >8" for=20
snow and sleet probabilities where they are high (>70% chances)=20
from northwest VA and north- central MD along Parr's Ridge to the=20
Lower Susquehanna Valley, but below 50% over southern NJ, the MD=20
eastern shore, and south of Fredericksburg, VA. Still, the WSO=20
shows >50% chances for a warning-level snowfall as far south as=20
central VA on east through the northern DelMarVa and into southern=20
NJ due to the strong 850-700mb FGEN Saturday night and Sunday=20
morning that fosters snowfall rates that could ranges between=20
1-2"/hr just north of the warm nose and changeover to sleet. This=20
FGEN is so strong in several CAMs as it lifts northward into the=20
Northeast on Sunday, mostly in part to the extreme thermal=20
gradient in place, that a few instances of thundersnow shouldn't=20
be ruled out. Even for areas that don't remain 100 percent snow,=20
the combination of snow, sleet, and inclusion of some freezing rain
still support significant travel disruptions in these southern=20
areas as well.=20

The WSSI shows widespread Major Impacts (considerable disruptions
to daily life: dangerous to impossible driving conditions,=20
widespread closures, and disruptions to infrastructure) from the TX
Panhandle on east to the Ozarks, through the OH Valley, and all the
way to New England. Every major market along the I-95 metropolitan
corridor (Washington D.C. to Boston and even as far north as
Portland, ME) are expecting major impacts due to snow. The=20
D.C/Baltimore area on north to Philly and NYC are likely to see=20
some inclusion of sleet, but it will still result in significant=20
impacts when accounting for heavy snowfall that is expected to
exceed warning criteria (5-6"). Coastal New England, including the
Boston metro region could also see winds increase to near-blizzard
conditions as wind gusts increase to 30-40 mph due to the
strengthening surface low and continued high snowfall rates. A=20
reminder that bitterly cold temperatures will follow in wake of=20
this storm Monday and into the middle of the week throughout the=20
eastern U.S.. The snow/sleet impacts will linger well into next=20
week with rounds of re-freezing that keeps surfaces icy and=20
dangerous to both drive and walk on for the foreseeable future.=20
Those in the path of this storm should follow advice of local
officials.


Freezing Rain...

The most lasting and dangerous impact will come as a result of=20
significant to locally catastrophic ice accumulations due to=20
prolonged periods of freezing rain. Just like the swath of >6" of=20
snowfall, the areal coverage of high chances (>50%) in WPC's ice=20 probabilities exceeding one-quarter inch of ice accumulation is=20
both impressive and alarming. From east-central TX to southern AR,=20
northern LA, northern MS, the TN Valley, northern GA, the southern=20 Appalachians, and southern Mid-Atlantic, these regions are all=20
likely to experience anywhere from one-quarter to one-half inch of=20
ice. Widespread power outages and tree damage is likely in these=20
areas, especially from the Lower MS Valley, southern Appalachians,
central NC, and south-central VA, where there are also medium=20
chances (>50%) for ice accumulations over one-half inch.=20

It is parts of northwest AL, northern MS, south-central TN,
southeast AR, northern LA, far northern GA, the southern=20
Appalachians, and the NC Piedmont that are of greatest concern. WPC probabilities show low- to- moderate chances (20-40%) for ice=20
accumulations over 1 inch and higher probabilities (30-60%) across
parts of northern/northwestern MS. These areas are likely to=20
endure a crippling ice storm that will take days, if not weeks, of=20
clean up in addition to extended power outages while bitterly cold
temperatures linger into next week. This is demonstrated in a rare
Extreme Impact on the WSSI in parts of northern MS, northeast LA, and
the Southern Appalachians. The WSSI Extreme criteria references=20
the potential for "extensive and widespread closures, extremely=20
dangerous travel, and life- saving actions may be needed." Once=20
the freezing rain starts, dangerous travel will be common not only=20
during the event, but in the days in wake of the storm due to=20
prolonged sub- freezing temperatures that cause persistent re-=20
freezing on all untreated surfaces. The Key Messages for the=20
Extreme Cold are linked below (Key Message 1).

Farther east, freezing rain will reach southern VA, the DelMarVa
Peninsula, and as far north as the I-95 corridor from Washington
D.C. to Philadelphia. The southern VA Piedmont, including the=20
Richmond metro area, have medium chances (40-60%) for over one-=20
half inch of ice. The WSSI depicts Major Impacts from Richmond on=20
south along I-95 into NC. While most areas farther north towards=20
the Lower Delaware Valley, Washington D.C. into southern NJ should
largely remain sleet, it may transition to freezing rain for a=20
brief time by Sunday evening. WPC probabilities show low-to-=20
medium chances (30-60%) for over one- tench of an inch of ice=20
accumulations Sunday evening.


Key Messages for this system are linked below (Key Message 2)


Snell/Mullinax



...Extreme Cold & Winter Storm Key Messages are in effect. Please=20
see current Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!_vSUFosL_fNE974CSds0-9HtYtuDLS1ao9damo__bVfhY= Taja5j4kl65r1blGHh-4akoePTGVmNbnc9HyIXEP5PejZs$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!_vSUFosL_fNE974CSds0-9HtYtuDLS1ao9damo__bVfhY= Taja5j4kl65r1blGHh-4akoePTGVmNbnc9HyIXELnzOa_o$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 242008
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
308 PM EST Sat Jan 24 2026

Valid 00Z Sun Jan 25 2026 - 00Z Wed Jan 28 2026


...Ongoing major winter storm to bring crippling icing,=20
significant sleet, and heavy snow from the Southern Rockies/Plains=20
through the Southeast and up the Atlantic Coast into New England...

Meteorological Overview...
Forecast remains on track as a massive winter storm, set to=20
produce a swath of heavy snow, significant sleet, and dangerous ice accumulations, continues across the Southern Plains and begins to=20
expand into the Ohio and Tennessee Valleys this afternoon. By=20
tonight, wintry precipitation is expected to lift into the Mid-=20
Atlantic, and reach New England on Sunday. By the time this event=20
winds down late Monday, it will leave a trail of more than 2000=20
miles of wintry precipitation, in a nearly continuous path, from=20
New Mexico to Maine.

The driver of this event will be the interaction of a northern
stream trough diving out of Canada with a southern stream impulse
ejecting from near Baja California. As these features move eastward
through the weekend and interact into a more amplified and larger
trough over the eastern CONUS, impressive subtropical moisture=20
will spread east/northeast both from the Pacific and the Gulf, with
IVT exceeding the 97th climatological percentile according to
NAEFS. The rich moisture from the south will accompany strong=20
850-700mb WAA that results in classic over-runing along an area of=20
850-700mb FGEN stretching from atop the Southern Plains to the TN=20
VLY and southern Mid-Atlantic by tonight, reaching New England
Sunday, and then finally exiting the Atlantic Coast on Monday. In
addition to the classic overrunning/WAA precipitation, the
placement of the upper jet as it strengthens and pivots poleward,
will support intense bands of snowfall (cross sections suggest a
high threat for CSI and even potential CI within the strongest WAA)
which will support snowfall rates of 1-2+"/hr at times where it is
all snow, and intense sleet/freezing rain rates in mixed zones.

Farther to the east, an intense CAD (Cold Air Damming) signature=20
will develop east of the Appalachians, with intense dewpoint
depressions of 20-30F during precipitation overrunning. While it
will take a while to saturate this to result in precipitation at
the surface, the intensity of this high with cold isallobaric
drainage aided both by mid-level confluence to the north and
precipitation falling into this wedge will enhance the CAD and
result in long duration mixed precipitation as the WAA pushes a
warm nose aloft (generally 800-700mb). This will support heavy
icing and sleet lifting northward into the Mid-Atlantic on Sunday,
and potentially as far as the south coast of New England as well.

With intense IVT pushing PWs to above the 99th percentile, there
will be plentiful moisture to work with everywhere from Texas
through New England. This will support heavy precipitation
accumulations regardless of p-type, so substantial impacts are
expected for a large swath of the nation. The heaviest snow is
expected from the Ohio Valley into the Northeast (more outlined
below), but an impressive jet-forced band of snow is also likely
from the Texas Panhandle through the Mid-Mississippi Valley.
Farther south, crippling icing is expected for parts of
AR/LA/MS/TN, as well as the Carolinas, with exceptional sleet
accumulations of several inches progged in between the snow and ice
from Arkansas through Kentucky, and then for portions of the Mid-
Atlantic as well.\


Heavy Snow/Sleet...
Snow will be winding down across the Southern Plains after 00Z=20
this evening (the start of the forecast period) but remain across=20
NM and of course farther east into AR/MO. This still supports an=20 astonishingly long swath of >6" of snowfall from NM to ME.=20

=46rom the Southern Plains through the Ohio Valley, 72-hr WPC
probabilities (so the entire forecast period although snowfall
should generally be a 24-hr period, a heavy band of snowfall on the
NW side of the low and within the strengthening jet streak will
support 1+"/hr snowfall as reflected by the WPC prototype snowband
tool. With this band likely translating along its long axis, heavy
snowfall will have a temporal extent sufficient for more than 8
inches (30-50% chance from the TX Panhandle through SW MO,
increasing to 90%+ in the Ohio Valley where more than 12 inches is
also likely (50-70% chance) before snow wanes from SW to NE on
Sunday. Locally 15+ inches is possible across southern OH.=20

The heaviest snow is likely from Pennsylvania through New England
where p-type changes are not likely. This is also where the longest
duration of heavy snowfall within both WAA banded structures and
then potentially a more pivoting/translating band will develop as
secondary low pressure skirts off the Mid-Atlantic coast and just
inside the Benchmark (40N/70W). This will support a longer
duration of 1-2+"/hr snowfall, and WPC 72-hr probabilities reach
above 70% for 12+ inches, and locally as much as 2 feet is possible
(especially in the Worcester Hills, Berkshires, and Catskills, as
well north of Boston along the coastal front) where WPC
probabilities for 24" are 10-30%. However, this will be a
widespread 12+" snowfall event for most of southern and central New
England as well as PA.

In addition, with the intense WAA, a warm nose aloft (generally
800-700mb) will gradually create a warm nose above 0C shifting
through the Mid-Atlantic, with additional warm nose/sleet impacts
expected from AR and into TN and KY. The cold depth below this warm
nose appears to be in many places above the 75th-90th percentile
for freezing rain, indicating primary sleet for these areas as
p-type transition occurs, with significant sleet accumulations of multiple-inches expected. This will result in tremendous impacts to
travel in these areas.

The WSSI shows widespread Major Impacts (considerable disruptions
to daily life: dangerous to impossible driving conditions,=20
widespread closures, and disruptions to infrastructure) from the TX
Panhandle on east to the Ozarks, through the OH Valley, and all the
way to New England. Every major market along the I-95 metropolitan
corridor (Washington D.C. to Boston and even as far north as
Portland, ME) are expecting major impacts due to snow. The=20
D.C/Baltimore area on north to Philly and NYC are likely to see=20
some inclusion of sleet, but it will still result in significant=20
impacts when accounting for heavy snowfall that is expected to
exceed warning criteria (5-6"). A reminder that bitterly cold=20
temperatures will follow in wake of this storm through the middle=20
of next week throughout the eastern U.S., so snow/sleet impacts=20
will linger for many days even after precipitation ends.


Freezing Rain...
The most lasting impact will come as a result of significant to=20
locally catastrophic ice accumulations due to prolonged periods of=20
freezing rain. Just like the swath of >6" of snowfall, the areal=20
coverage of high chances (>50%) in WPC's ice probabilities=20
exceeding one-quarter inch of ice accumulation is expansive from=20
eastern TX through southern KY, with a secondary area east of the=20
Cumberland Gap from northern GA through southeast VA and including=20
much of the Carolinas. In these regions, at least 0.25" of ice is=20
expected to be widespread, with a more narrow corridor embedded=20
within of at least 0.5" (50-90%), highest in northern MS and=20
western TN, but some higher potential also exists in GA/SC where=20
locally more than 1 inch (a catastrophic accumulation for damage=20
and prolonged impacts of a week or more) is possible (10-30%=20
chance).

For LA, MS, TN, this ice accumulation is "additional" beyond what
will occur before 00Z (6pm CST), so local amounts above 1" are
actually expected to be more widespread than the updated
probabilities suggest. This produces a 20-40% chance of Extreme
impacts (extensive and widespread disruptions to infrastructure)
and these impacts could linger for a week or more where icing is
most significant. With very cold weather in place, this will become
a life-threatening situation, with potentially impossible travel
due to downed trees and power lines.


Key Messages for this system are linked below (Key Message 2).
Key messages for the widespread extreme cold are linked below as
well (Key Message 1).


...Great Lakes...
Day 3...

Broad cyclonic flow will persist across the east, but an embedded
shortwave within this trough will dig out of Alberta Monday night
and then cross the Great Lakes from northwest to southeast during
Tuesday. This will enhance CAA, leading to another round of lake
effect snow (LES), although the duration and intensity of this
event should be modest overall, some moderate accumulations are
still expected beginning D3 /00Z Tuesday to 00Z Wednesday/ and
lingering beyond this forecast period. LES from Lake Erie should be
minimal as that lake is now ice covered according to GLERL, but
elsewhere, ***WPC probs...heaviest***


Snell/Weiss


...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!5yyp-eYgnqjdhXbnMGZ5F6MbfMH3V2jDjKFhtuPp72HzG= v1utrZAGBCuWMZw740nbStEiOYlG4pGhUeyanMrSk83qWE$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!5yyp-eYgnqjdhXbnMGZ5F6MbfMH3V2jDjKFhtuPp72HzG= v1utrZAGBCuWMZw740nbStEiOYlG4pGhUeyanMrxvhmuX8$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 242013
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
313 PM EST Sat Jan 24 2026

Valid 00Z Sun Jan 25 2026 - 00Z Wed Jan 28 2026


...Ongoing major winter storm to bring crippling icing,=20
significant sleet, and heavy snow from the Southern Rockies/Plains=20
through the Southeast and up the Atlantic Coast into New England...

Meteorological Overview...
Forecast remains on track as a massive winter storm, set to=20
produce a swath of heavy snow, significant sleet, and dangerous ice accumulations, continues across the Southern Plains and begins to=20
expand into the Ohio and Tennessee Valleys this afternoon. By=20
tonight, wintry precipitation is expected to lift into the Mid-=20
Atlantic, and reach New England on Sunday. By the time this event=20
winds down late Monday, it will leave a trail of more than 2000=20
miles of wintry precipitation, in a nearly continuous path, from=20
New Mexico to Maine.

The driver of this event will be the interaction of a northern
stream trough diving out of Canada with a southern stream impulse
ejecting from near Baja California. As these features move eastward
through the weekend and interact into a more amplified and larger
trough over the eastern CONUS, impressive subtropical moisture=20
will spread east/northeast both from the Pacific and the Gulf, with
IVT exceeding the 97th climatological percentile according to
NAEFS. The rich moisture from the south will accompany strong=20
850-700mb WAA that results in classic over-runing along an area of=20
850-700mb FGEN stretching from atop the Southern Plains to the TN=20
VLY and southern Mid-Atlantic by tonight, reaching New England
Sunday, and then finally exiting the Atlantic Coast on Monday. In
addition to the classic overrunning/WAA precipitation, the
placement of the upper jet as it strengthens and pivots poleward,
will support intense bands of snowfall (cross sections suggest a
high threat for CSI and even potential CI within the strongest WAA)
which will support snowfall rates of 1-2+"/hr at times where it is
all snow, and intense sleet/freezing rain rates in mixed zones.

Farther to the east, an intense CAD (Cold Air Damming) signature=20
will develop east of the Appalachians, with intense dewpoint
depressions of 20-30F during precipitation overrunning. While it
will take a while to saturate this to result in precipitation at
the surface, the intensity of this high with cold isallobaric
drainage aided both by mid-level confluence to the north and
precipitation falling into this wedge will enhance the CAD and
result in long duration mixed precipitation as the WAA pushes a
warm nose aloft (generally 800-700mb). This will support heavy
icing and sleet lifting northward into the Mid-Atlantic on Sunday,
and potentially as far as the south coast of New England as well.

With intense IVT pushing PWs to above the 99th percentile, there
will be plentiful moisture to work with everywhere from Texas
through New England. This will support heavy precipitation
accumulations regardless of p-type, so substantial impacts are
expected for a large swath of the nation. The heaviest snow is
expected from the Ohio Valley into the Northeast (more outlined
below), but an impressive jet-forced band of snow is also likely
from the Texas Panhandle through the Mid-Mississippi Valley.
Farther south, crippling icing is expected for parts of
AR/LA/MS/TN, as well as the Carolinas, with exceptional sleet
accumulations of several inches progged in between the snow and ice
from Arkansas through Kentucky, and then for portions of the Mid-
Atlantic as well.\


Heavy Snow/Sleet...
Snow will be winding down across the Southern Plains after 00Z=20
this evening (the start of the forecast period) but remain across=20
NM and of course farther east into AR/MO. This still supports an=20 astonishingly long swath of >6" of snowfall from NM to ME.=20

=46rom the Southern Plains through the Ohio Valley, 72-hr WPC
probabilities (so the entire forecast period although snowfall
should generally be a 24-hr period, a heavy band of snowfall on the
NW side of the low and within the strengthening jet streak will
support 1+"/hr snowfall as reflected by the WPC prototype snowband
tool. With this band likely translating along its long axis, heavy
snowfall will have a temporal extent sufficient for more than 8
inches (30-50% chance from the TX Panhandle through SW MO,
increasing to 90%+ in the Ohio Valley where more than 12 inches is
also likely (50-70% chance) before snow wanes from SW to NE on
Sunday. Locally 15+ inches is possible across southern OH.=20

The heaviest snow is likely from Pennsylvania through New England
where p-type changes are not likely. This is also where the longest
duration of heavy snowfall within both WAA banded structures and
then potentially a more pivoting/translating band will develop as
secondary low pressure skirts off the Mid-Atlantic coast and just
inside the Benchmark (40N/70W). This will support a longer
duration of 1-2+"/hr snowfall, and WPC 72-hr probabilities reach
above 70% for 12+ inches, and locally as much as 2 feet is possible
(especially in the Worcester Hills, Berkshires, and Catskills, as
well north of Boston along the coastal front) where WPC
probabilities for 24" are 10-30%. However, this will be a
widespread 12+" snowfall event for most of southern and central New
England as well as PA.

In addition, with the intense WAA, a warm nose aloft (generally
800-700mb) will gradually create a warm nose above 0C shifting
through the Mid-Atlantic, with additional warm nose/sleet impacts
expected from AR and into TN and KY. The cold depth below this warm
nose appears to be in many places above the 75th-90th percentile
for freezing rain, indicating primary sleet for these areas as
p-type transition occurs, with significant sleet accumulations of multiple-inches expected. This will result in tremendous impacts to
travel in these areas.

The WSSI shows widespread Major Impacts (considerable disruptions
to daily life: dangerous to impossible driving conditions,=20
widespread closures, and disruptions to infrastructure) from the TX
Panhandle on east to the Ozarks, through the OH Valley, and all the
way to New England. Every major market along the I-95 metropolitan
corridor (Washington D.C. to Boston and even as far north as
Portland, ME) are expecting major impacts due to snow. The=20
D.C/Baltimore area on north to Philly and NYC are likely to see=20
some inclusion of sleet, but it will still result in significant=20
impacts when accounting for heavy snowfall that is expected to
exceed warning criteria (5-6"). A reminder that bitterly cold=20
temperatures will follow in wake of this storm through the middle=20
of next week throughout the eastern U.S., so snow/sleet impacts=20
will linger for many days even after precipitation ends.


Freezing Rain...
The most lasting impact will come as a result of significant to=20
locally catastrophic ice accumulations due to prolonged periods of=20
freezing rain. Just like the swath of >6" of snowfall, the areal=20
coverage of high chances (>50%) in WPC's ice probabilities=20
exceeding one-quarter inch of ice accumulation is expansive from=20
eastern TX through southern KY, with a secondary area east of the=20
Cumberland Gap from northern GA through southeast VA and including=20
much of the Carolinas. In these regions, at least 0.25" of ice is=20
expected to be widespread, with a more narrow corridor embedded=20
within of at least 0.5" (50-90%), highest in northern MS and=20
western TN, but some higher potential also exists in GA/SC where=20
locally more than 1 inch (a catastrophic accumulation for damage=20
and prolonged impacts of a week or more) is possible (10-30%=20
chance).

For LA, MS, TN, this ice accumulation is "additional" beyond what
will occur before 00Z (6pm CST), so local amounts above 1" are
actually expected to be more widespread than the updated
probabilities suggest. This produces a 20-40% chance of Extreme
impacts (extensive and widespread disruptions to infrastructure)
and these impacts could linger for a week or more where icing is
most significant. With very cold weather in place, this will become
a life-threatening situation, with potentially impossible travel
due to downed trees and power lines.


Key Messages for this system are linked below (Key Message 2).
Key messages for the widespread extreme cold are linked below as
well (Key Message 1).


...Great Lakes...
Day 3...

Broad cyclonic flow will persist across the east, but an embedded
shortwave within this trough will dig out of Alberta Monday night
and then cross the Great Lakes from northwest to southeast during
Tuesday. This will enhance CAA, leading to another round of lake
effect snow (LES), although the duration and intensity of this
event should be modest overall, some moderate accumulations are
still expected beginning D3 /00Z Tuesday to 00Z Wednesday/ and
lingering beyond this forecast period. LES from Lake Erie should be
minimal as that lake is now ice covered according to GLERL, but
elsewhere, WPC probabilities are moderate for 4+ inches near the
Tug Hill Plateau, and moderate (10-50%)for 2+ inches along the=20
western shore of the L.P. of MI as well as parts of the U.P.


Snell/Weiss



...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!5W-O6S2TsavdXtQOUAK8oUfK4CWv9hDLB6maEn-RBEC8z= dxGx2_1hRti8HNuSE65ZONdrM6PSUgE9zjorHLbn-2g7N0$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!5W-O6S2TsavdXtQOUAK8oUfK4CWv9hDLB6maEn-RBEC8z= dxGx2_1hRti8HNuSE65ZONdrM6PSUgE9zjorHLbAtBCRDQ$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 250741
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
241 AM EST Sun Jan 25 2026

Valid 12Z Sun Jan 25 2026 - 12Z Wed Jan 28 2026


...Ongoing major winter storm to bring crippling icing,=20
significant sleet, and heavy snow from the Southern Rockies/Plains=20
through the Southeast and up the Atlantic Coast into New England...

Meteorological Overview...
Forecast remains on track as a massive winter storm is underway
across a significant portion of the country, currently extending=20
from the southern Rockies to the Mid-Atlantic early this morning.
By the start of the forecast period (12z Sun), widespread moderate
to heavy snow, sleet, and freezing rain is expected to span from=20
New Mexico to New York and continue to primarily impact regions=20
from the Ohio/Tennessee valleys and Mid-Atlantic to New England
through the overnight hours tonight. This event is forecast to=20
gradually wane across New England and the Interior Northeast on=20
Monday.

The driver of this winter storm is the interaction of a northern=20
stream trough diving out of the north-central U.S. this morning
along with a few southern stream impulses ejecting from the
southern Rockies and Plains. As these features accelerate eastward
today and interact into a more amplified and larger trough over=20
the central CONUS tonight, impressive subtropical moisture will
continue spreading east/northeast both from the Pacific and the=20
Gulf, with IVT exceeding the 97.5th climatological percentile=20
according to NAEFS. The rich moisture from the south will accompany
strong 850-700mb WAA that results in classic over- running along=20
an area of 850-700mb FGEN stretching from atop the Mid-MS and OH/TN
VLY to the Mid- Atlantic this morning, reaching New England this=20
evening and then finally exiting the Atlantic Coast on Monday. In=20
addition to the classic overrunning/WAA precipitation, the=20
placement of the upper jet as it strengthens and pivots poleward,=20
will support intense bands of snowfall (cross sections suggest a=20
high threat for CSI and even potential CI within the strongest WAA)
which will support snowfall rates of 1-2+"/hr at times where it is
all snow, and intense sleet/freezing rain rates in mixed zones.

Farther to the east, the intense CAD (Cold Air Damming) signature=20=20
east of the Appalachians will only slightly retreat through
tonight. With rapid warming aloft due to increasing southerly 850mb
winds over 50 kts and subfreezing temperatures remaining in the=20
low- levels, sleet is expected to be as far north as southern MD by
12z this morning and continuing marching northward through the day
as far as the southern New England coastline. This will cut down on
snowfall totals along I-95 from Washington D.C. to NYC, and will
also increase the potential for ptype to turn towards dangerous
freezing rain by late this afternoon.

With intense IVT pushing PWs to above the 99th percentile, there
will be plentiful moisture to work with everywhere from the OH VLY
through New England. This will support heavy precipitation=20
accumulations regardless of p-type, so substantial impacts are=20
expected for a large swath of the nation. The heaviest snow is=20
expected from the Ohio Valley into the Northeast (more outlined=20
below). Farther south, crippling icing is expected for parts of=20
AR/LA/MS/TN early today, as well as the Carolinas and Virginia
through tonight, with exceptional sleet accumulations of several=20
inches progged in between the snow and ice from Arkansas through=20
Kentucky, and then for portions of the Mid- Atlantic as well.


Heavy Snow/Sleet...
Snow will be winding down across the Southern Plains and Mid-MS VLY
by 12z this morning, but continues just east through the OH VLY. This
still supports an long swath of >6" of snowfall from IN to ME and
an increasing potential for >18" across the Interior Northeast and
New England.

48-hr WPC probabilities (most snow occurring within the first=20
24-hr period), are high (>70%) for an additional 8"+ from central=20
OH through central ME and most of New England. Probabilities for=20
18"+ have increased and are 50-80% across Upstate NY through much=20
of New England as far north as central VT/NH. A heavy band of=20
snowfall on the NW side of the low and within the strengthening jet
streak will support 1+"/hr snowfall across the Ohio Valley through
this afternoon as reflected by the WPC prototype snowband tool.=20
With this band likely translating along its long axis, heavy=20
snowfall will have a temporal extent sufficient for more than 8=20
inches. Locally 15+ inches is possible across southern OH.=20

The heaviest snow from this event is likely across New England and
the Interior Northeast where p-type changes are not likely. This=20
is also where the longest duration of heavy snowfall within both=20
WAA banded structures and then potentially a more=20
pivoting/laterally translating band will develop as secondary low=20
pressure skirts off the Mid- Atlantic coast and just inside the=20
Benchmark (40N/70W). This will support a longer duration of=20
2+"/hr snowfall, and WPC 48-hr probabilities reach above 90% for=20
12+ inches, and locally as much as 2 feet is possible (especially=20
in the Worcester Hills, Berkshires, and Catskills, as well north of
Boston along the coastal front) where WPC probabilities for 24"=20
are 20-40%. WPC's Snowband Probability Tracker (SPT) using the 00z
HREF is very impressive for 1-2"+/hr rates around 18Z near=20
northern NJ and eventually across New England beginning around 21Z
and lasting across eastern New England until 06Z tonight.=20
Regarding coverage of heavy snow, this will be a widespread 12"+=20
snowfall event for most of southern and central New England as well
as central/northern PA.

In addition, with the intense WAA, a warm nose aloft (generally
800-700mb) will gradually create a warm nose above 0C shifting
through the Mid-Atlantic. The cold depth below this warm nose=20
appears to be in many places above the 75th-90th percentile for=20
freezing rain, indicating primary sleet for these interior areas=20
as p-type transition occurs, with significant sleet accumulations=20
of multiple-inches expected. This will result in tremendous impacts
to travel in these areas.

The WSSI shows widespread Major Impacts (considerable disruptions
to daily life: dangerous to impossible driving conditions,=20
widespread closures, and disruptions to infrastructure) from the=20
OH VLY to New England. Every major market along the I-95=20
metropolitan corridor (Washington D.C. to Boston and even as far=20
north as Portland, ME) are expecting major impacts due to snow
amounts. The D.C/Baltimore area on north to Philly and NYC are=20
likely to see some inclusion of sleet and potentially some freezing
rain, but it will still result in significant impacts when=20
accounting for heavy snowfall that is expected to exceed warning=20
criteria (5-6"). Gusty winds increasing with the developing=20
surface low off the Mid-Alantic coast may also lead to a brief=20
period of near-blizzard conditions across eastern New England,=20
including Boston, late tonight. A reminder that bitterly cold=20
temperatures will follow in wake of this storm through the middle=20
of next week throughout the eastern U.S., so snow/sleet impacts=20
will linger for many days even after precipitation ends.

Freezing Rain...
The most lasting impact will come as a result of significant to=20
locally catastrophic ice accumulations due to prolonged periods of=20
freezing rain. Just like the swath of >6" of snowfall, the areal=20
coverage of impactful freezing rain remains expansive across the=20
Mid- South, where the event concludes by midday today and a=20
secondary area east of the Cumberland Gap from northern GA through=20
central VA and southern MD, including much of the Carolinas. In=20
these regions, at least 0.25" of total ice is expected to be=20
widespread, with a more narrow corridor embedded within of at least
an additional 0.5" (30-60%), highest today across the NC Piedmont
into south-central VA. This amount of freezing rain can create
widespread power outages and tree damage, as well as treacherous to
impossible travel at times.

For LA, MS, TN, ice accumulation is "additional" beyond what will=20
occur before 12Z (6am CST), so local amounts above 1" are actually
expected to be much more widespread than the very low=20
probabilities suggest for solely today's precipitation. The=20
greatest additional icing after 12Z today is located across the=20
Mid- Atlantic, where up to 0.5" is possible. With very cold weather
in place, this will become a life- threatening situation where=20
freezing rain amounts are highest (including the Lower MS VLY and=20
Mid-South) with potentially impossible travel due to downed trees=20
and power lines.


Key Messages for this system are linked below (Key Message 2).
Key messages for the widespread extreme cold are linked below as
well (Key Message 1).


...Great Lakes...
Days 2-3...

Broad cyclonic flow will persist across the east, but an embedded
shortwave within this trough will dig out of Alberta Monday night
and then cross the Great Lakes from northwest to southeast during
Tuesday. This will enhance CAA, leading to another round of lake
effect snow (LES), although the duration and intensity of this
event should be modest overall, some moderate accumulations are
still expected beginning D2-3 and lingering beyond this forecast=20
period. LES from Lake Erie should be minimal as that lake is now=20
ice covered according to GLERL and should continue to see ice
thicken with very cold temperatures in place, but elsewhere, WPC=20 probabilities are high for 4+ inches near the Tug Hill Plateau.


Snell/Weiss




...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!9sseXzdxj0AGHqtE9PxBDvpaCHTgyf0kBlV0VQClBi97u= cbSjEzZJILpGM3a97dsD08_MPYg2KvCXzcmJFn55hXmNHY$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!9sseXzdxj0AGHqtE9PxBDvpaCHTgyf0kBlV0VQClBi97u= cbSjEzZJILpGM3a97dsD08_MPYg2KvCXzcmJFn5V8ppWtM$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 251820
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
120 PM EST Sun Jan 25 2026

Valid 00Z Mon Jan 26 2026 - 00Z Thu Jan 29 2026


...Mid-Atlantic and Northeast...
Days 1-2...

The expansive winter storm will wind down across the Central
Plains and Mid-South today, but significant impacts will persist
across the Ohio Valley, Mid-Atlantic, and Northeast tonight and
Monday.

This morning, the GOES-E water vapor imagery tells the take, with
an impressive plume of moisture stretching from Texas into southern
Canada, with a clear baroclinic leaf expanding over the TN/OH
Valleys. The upper low is spinning over TX and this will lift
northward into the Ohio Valley today, while secondary low pressure
development occurs off the Mid-Atlantic coast this afternoon. This
secondary low pressure will become dominant and strengthen as it
tracks south of New England, with the most significant winter
weather and impacts shifting into New England tonight and Monday.
The trailing upper trough will move across the Great Lakes Monday,
helping to drive an inverted trough back across New England even as
the primary low departs, and light although the heaviest snow
should end Monday night, light snow may persist in this area into
Tuesday morning.=20

This evolution will result in impressive additional snow amounts
(after 00Z this evening) from the higher terrain of WV/PA northeast
through Upstate NY and all of New England. The heaviest snowfall is
expected across Upstate NY and New England where WPC probabilities
indicate a high risk (>90%) for at least 8 inches, with 12-18"
possible (30-50% chance) for the Greens, Whites, and coastal SW=20
Maine/far northern MA thanks to a coastal front evolution. Snowfall
rates will be extreme at times, potentially reaching 2-3"/hr as=20
progged by the WPC prototype snowband tool due to strong WAA=20
overlapping fgen which may result in CSI/CI (and possible=20
thundersnow). The intense WAA in the 850-700mb will drive a warm=20
nose above 0C as far north as coastal CT/RI/Cape Cod, so some=20
transition to sleet is likely, but otherwise a very cold airmass=20
will allow SLRs to be above climo (but dropping during the event)=20
which will help that efficient snow growth. The DGZ is quite=20
elevated, so the best ascent will not cross-hatch into the snow=20
growth region in most areas, but nevertheless, robust moisture on=20
IVT exceeding the 90th percentile will wring out to this heavy=20
snow, and it is possible some 48-hr total snowfall will reach more=20
than 2 feet in parts of New England, with widespread 6-12" covering
most of the Mid-Atlantic, Ohio Valley, and rest of the Northeast=20
before this event winds down.

Although most of the accumulation will occur by 12Z Monday, the
aforementioned inverted trough linking back to the upper low may
allow for wrap-around snowfall to linger much of Monday and into
Monday night adding a few more inches of cold fluffy snow to the
area, especially New England and Upstate NY. WSSI-P indicates
continues high probabilities (>80%) for major impacts, and the I-95
corridor between NYC and Portland, ME will be treacherous through
Monday.

Farther south, freezing rain will continue for parts of the Mid-
Atlantic, especially northern NC, southeast VA, and potentially
along the I-95 corridor as far north as NYC. While additional
freezing rain amounts are expected to be modest as precip begins to
wind down (WPC probabilities suggest a 50-70% chance of at least
0.1" of ice), this will be on top of prior icing to enhance impacts
including treacherous travel and power outages. With extremely cold temperatures likely after this storm persisting for many days, any
power outages will become a life-threatening situation for parts of
the Mid-Atlantic states.


...Great Lakes...
Days 1-3...

Broad cyclonic flow will persist across the east, and multiple
embedded shortwaves will ride through this trough out of Canada,
each one acting to reinforce cold advection (CAA) across the Great
Lakes to support rounds of lake effect snow (LES). While GLERL
indicates that water temperatures are cooling, Lake Erie is
entirely ice covered, and with the very cold temperatures this week
continuing, additional ice cover is expected. However, there
should still be sufficient instability and moisture to support LES
each day through the forecast period. LES is not expected to be
extremely intense, although will be efficient downstream of Lake
Ontario towards the Tug Hill Plateau at times, and it is this area
that is expected to receive the heaviest LES. WPC probabilities for
all 3 days indicate a high chance (>70%) for at least 8 inches east
of Lake Ontario, with lower probabilities for 8+ inches (10-30%
chance) southeast of Lake Michigan and across the eastern U.P. on
the south shore of Lake Superior.

Weiss



...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!5X0xN7MdHtpiv0Oq5XxTtzmHSf-mjyyl5Z8e4q_9Z6UZb= c44QpuSi4xTywscDvjJby3zed3keoBg7ZLpxNDxroebvd4$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!5X0xN7MdHtpiv0Oq5XxTtzmHSf-mjyyl5Z8e4q_9Z6UZb= c44QpuSi4xTywscDvjJby3zed3keoBg7ZLpxNDxHkG_Cm8$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 260707
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
207 AM EST Mon Jan 26 2026

Valid 12Z Mon Jan 26 2026 - 12Z Thu Jan 29 2026


...New England...
Day 1...

The major winter storm that swept over the Nation the last few
days will continue to gradually exit the Northeast today, with
lingering additional snowfall across parts of New England. By the
start of the forecast period (12z Mon), the primary surface low
will be sliding east into the open Atlantic and only provide for
some favorable ocean-enhanced snow from the south coast of ME to
eastern MA. Otherwise, mostly light to moderate snow will be
associated with a weakening 850mb low tracking across northern New
England. Additional snowfall amounts through tonight are expected
to range from 3-5", with the highest probabilities (50-80%) for
greater than 4" extending from the northern coast of MA to eastern
ME. Storm total snowfall amounts from Sunday through the D1 period
are expected to exceed 20" across parts of New England.


...Great Lakes...
Days 1-3...

Broad cyclonic flow will persist across the east, and multiple
embedded shortwaves will ride through this trough out of Canada,
each one acting to reinforce cold advection (CAA) across the Great
Lakes to support rounds of lake effect snow (LES). While GLERL
indicates that water temperatures are cooling, Lake Erie is
entirely ice covered, and with the very cold temperatures this week
continuing, additional ice cover is expected. However, there
should still be sufficient instability and moisture to support LES
each day through the forecast period. LES is not expected to be
extremely intense, although will be efficient downstream of Lake
Ontario towards the Tug Hill Plateau at times, and it is this area
that is expected to receive the heaviest LES. WPC probabilities for
all 3 days indicate a high chance (>80%) for at least 12 inches
east of Lake Ontario, with lower probabilities for 8+ inches
(30-60% chance) east of Lake Michigan and across the eastern U.P.
on the south shore of Lake Superior.


Snell



$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 262022
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
322 PM EST Mon Jan 26 2026

Valid 00Z Tue Jan 27 2026 - 00Z Fri Jan 30 2026


...New England...
Day 1...

The final bands of the major winter storm shift east from New
England this evening. A couple additional inches are possible after
00Z over much of Maine down through the Mass coast.


...Great Lakes...
Days 1-3...

Broad cyclonic flow and trough passages persist across the Great
Lakes as low pressure over Hudson Bay shifts south over Ontario
through Thursday. These will produce rounds of lake effect snow=20
(LES) particularly starting Tuesday behind a notable upper trough
passage. According to GLERL, Lake Erie is essentially ice=20
covered, so available moisture will be limited there while Lakes=20
Superior and Ontario remain largely. Westerly flow allows Day 2/3=20
PWPF for >6" are over 50% in the Tug Hill and just Day 2 for the
eastern U.P. of Michigan.


...Cascades...
Days 2/3...

The next trough axis shunts the powerful ridge east Tuesday night
with precip over the WA Cascades then through Thursday. Snow levels
rise from 4000 to 5000ft over the WA Cascades Wednesday through
Thursday. PWPF for >6" is 40-70% above the snow level (above pass
level) by Thursday.


The probability for significant icing is less than 10 percent.



Jackson




...Extreme Cold Key Messages are linked below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!-0TZxpay_jM8Z4Q34rmMmud52o6t8jkHOE9b3VqfOemR-= ZzRDBrxLmQXLRJn74txeFUITeYsrY6M3nwWigr62iJQsj4$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 270733
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
233 AM EST Tue Jan 27 2026

Valid 12Z Tue Jan 27 2026 - 12Z Fri Jan 30 2026


...Great Lakes...
Days 1-3...

Broad cyclonic flow and trough passages persist across the Great
Lakes as low pressure over Hudson Bay shifts south over Ontario
through Thursday. These will produce rounds of lake effect snow=20
(LES) beginning today behind a notable upper trough passage. 850mb
temperatures will remain quite cold during this period, with
temperatures around -18 to -24C, and below the 10th climatological
percentile. According to GLERL, Lake Erie is essentially ice=20
covered, so available moisture will be limited there while Lakes=20
Superior and Ontario remain largely open. Westerly flow will
continue across the Lower Great Lakes through Thursday night, with
northerly flow more likely on Day 3 across the Upper Great Lakes,
This allows Days 1-3 PWPF for >8" over 50% in the Tug Hill and for
the eastern U.P. of Michigan. The heaviest snowfall is no doubt
most likely downwind of Lake Ontario and the Tug Hill, where 50-60% probabilities for >18" reach the shoreline of Oswego county.


...Cascades...
Days 2/3...

The next trough axis to near the Pacific Northwest shunts the=20
powerful western ridge eastward Tuesday night, with precip over=20
the WA Cascades then through Thursday. Snow levels rise from 4000=20
to 5000ft over the WA Cascades Wednesday through Thursday. PWPF for

6" is 40-70% above the snow level (above pass level) by Thursday.

The probability for significant icing is less than 10 percent.



Snell





...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!8NunqgJMY9ONsq94cDZxgfNTy_qFZpb-PYrxM2rTB5EIS= h2M4WxUege40SO-B-z28uH25Ynjwag2vrjv-7YR7oHbKF4$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 271931
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
231 PM EST Tue Jan 27 2026

Valid 00Z Wed Jan 28 2026 - 00Z Sat Jan 31 2026


...Great Lakes...
Days 1-3...

The seemingly endless cyclonic flow that has kept the LES machine=20
cranking over snow belts of the Great Lakes looks to continue
through the remainder of the work-week. Frigid 850mb temperatures=20
will persist with temperatures around -18 to -24C, which are below
the 10th climatological percentile. According to GLERL, Lake Erie=20
is essentially ice covered, so available moisture will be limited=20
there while Lakes Superior and Ontario remain largely open. W-NWrly
low-level winds will continue through Wednesday before the approach
of a sharp 500mb shortwave pivots through and shifts winds more out
of the N-NNW by Thursday. Northerly flow continues Friday as high
pressure builds in over the Northern Plains. 72-hour WPC
probabilities depict high chances (>70%) for snowfall totals >4"
over the northern tier of the Michigan U.P. and down wind of Lake=20
Ontario to the south of an over the Tug Hill. The area with the=20
best odds of seeing over a foot of snow over the next few days are=20
near the Oswego, NY area where WPC probabilities for over a foot of
snow are in the moderate range of probabilities (40-60%).=20


...Cascades & Olympics...
Days 1-3...

A series of storm systems tracking into the Gulf of Alaska will
direct rounds of moisture and WAA at western WA through the
remainder of the week. Strong upslope flow should support locally
heavy snowfall totals as low as 4,000ft, but most heavy snow will=20
reside in the more remote areas above 5,000ft. Snow levels rise=20
from 4000 to 5000ft over the WA Cascades Wednesday through=20
Thursday. By Friday, snow levels approach 6,000ft by Friday in
western WA. WPC probabilities for >4" is high (>70%) around Stevens
Pass, but lighter accumulations around Snoqualmie are anticipated
at this moment given the higher snow levels.

...Northern & Central Plains...
Days 2-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a
nearby 850mb front to support periods of snow from the northern
High Plains on south in the the central High Plains. Snow is not
expected to be overly heavy, although the Black Hills through
orographic lifting may be able to see snowfall amounts surpass 6".
This is supported in WPC probabilities which show moderate-to-high
chances (50-70%) for >4" of snow in the Black Hills, and low
chances (10-30%) in their peaks for >8". Elsewhere, from eastern MT
on south and east through the Missouri River Valley, most snowfall accumulations are likely to range between 1-3". Some hazardous
travel is possible, especially where roads temperatures are at or
below freezing in wake of the recent extreme cold.


...Southern Appalachians & Mid-Atlantic...
Days 3-3.5...

...Confidence In Impactful Snowfall Increasing For the Southern=20
Appalachians and Southern Mid-Atlantic...

To say there remains a large amount of model spread in the
potential winter storm beyond Day 3 would be an understatement. In
the past 24 hours, ensemble guidance have flipped camps to where
the GEFS are the snowier members, CMCE are more in the middle, and
the EC-EPS are trending less snowy. It is worth noting that AI=20
ensemble membership are not as snowy as the GEFS, but show a little
more snow than the EC-EPS, making this an interesting test in how=20
the AI ensemble membership performs.=20

Regarding the setup-- WPC Cluster Analysis shows this potential=20
winter storm comes down to several factors: 1) strength of the=20
emerging Great Lakes shortwave trough. 2) speed of the shortwave=20
trough. 3) tilt/amplitude of the shortwave trough as it tracks=20
east. 4) Confluence strength near Nova Scotia. They all work=20
together in an intricate dance that makes for difficulties in=20
modeling. A stronger/slower shortwave can buy time for confluence=20
over New England and Nova Scotia to weaken, giving the shortwave=20
more time to amplify, and allow for closer storm tracks to the=20
coast that bring heavy snow as far west as the I-95 corridor (some=20
GEFS members and some CMCE members). Where the shortwave is=20
stronger but progressive, heavier snowfall occurs but largely=20
closer to the coast and as far west as the NC Piedmont (CMCE=20
members, UK ensembles, split EC/GEFS members). If the shortwave=20
trough is more progressive and cannot separate itself from the=20
larger TPV to the east there is less amplification, it results in=20
a flatter and more positively/tilted shortwave trough, and thus the=20
storm remains largely out at sea (EPS, EC-AIFS ensembles, some=20
GEFS/CMCE members). It is worth noting that, while the EC-AIFS has=20
largely performed well inside of 5 days much of the winter season,=20
the EC-AIFS and ECMWF did suppress the track of the most recent=20
winter storm too much ~4-5 days out before correcting northward=20
inside of 72 hours out.

This setup is highly timing dependent; from the primary shortwave
trough currently east of Hudson Bay, to the interaction/spacing of
the 500mb cyclonic gyres in southeast Canada and south of Iceland
that promote the confluence ahead of the potential storm, to the=20
incoming Pacific shortwaves that track into western Canada and
adjust the strength/position of the western North America ridge.=20
There remain a host of embedded shortwaves that will work together=20
to create a complex storm evolution off the East Coast. Whatever=20
the current model solutions show beyond 72 hours out is unlikely to
be the final product. Expect additional model changes in the=20
coming days. If there is one thing that has increased in confidence
in the past 24 hours, it is the opportunity for coastal flooding=20
and beach erosion along the Mid-Atlantic coast. Please refer to our
"What We know, What We Don't Know" social media post for=20
additional information.

The one thing they do agree on is this upper trough tracks through
the OH Valley Friday afternoon with sufficient PVA and 850-500mb=20
mean layer moisture to support snow from central KY to the southern Appalachians through Friday evening. WPC probabilities do
show increasing chances for at least minor accumulations >2" over
KY and northeast TN, while there are low-chances (10-30%) for
snowfall totals >4" through early Saturday morning in the TN/NC Smokeys
and Blue Ridge of NC. Residents and those traveling to the=20
Carolinas on north up the East Coast will want to continue=20
following the forecasts from WPC and your local NWS WFO for the=20
latest regarding this potential winter storm.=20


The probability for significant icing is less than 10 percent.


Mullinax




...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!6VI14otitwAAstNrC60qAGwJSrOE6Zf0oLu0MtZRucHys= 6sfDSsnz6A0nRg5hdjsoJ-6sT4HYazaHiiRfGLVWtSFuMg$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 272009
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
309 PM EST Tue Jan 27 2026

Valid 00Z Wed Jan 28 2026 - 00Z Sat Jan 31 2026


...Great Lakes...
Days 1-3...

The seemingly endless cyclonic flow that has kept the LES machine=20
cranking over snow belts of the Great Lakes looks to continue
through the remainder of the work-week. Frigid 850mb temperatures=20
will persist with temperatures around -18 to -24C, which are below
the 10th climatological percentile. According to GLERL, Lake Erie=20
is essentially ice covered, so available moisture will be limited=20
there while Lakes Superior and Ontario remain largely open. W-NWrly
low-level winds will continue through Wednesday before the approach
of a sharp 500mb shortwave pivots through and shifts winds more out
of the N-NNW by Thursday. Northerly flow continues Friday as high
pressure builds in over the Northern Plains. 72-hour WPC
probabilities depict high chances (>70%) for snowfall totals >4"
over the northern tier of the Michigan U.P. and down wind of Lake=20
Ontario to the south of an over the Tug Hill. The area with the=20
best odds of seeing over a foot of snow over the next few days are=20
near the Oswego, NY area where WPC probabilities for over a foot of
snow are in the moderate range of probabilities (40-60%).=20


...Cascades & Olympics...
Days 1-3...

A series of storm systems tracking into the Gulf of Alaska will
direct rounds of moisture and WAA at western WA through the
remainder of the week. Strong upslope flow should support locally
heavy snowfall totals as low as 4,000ft, but most heavy snow will=20
reside in the more remote areas above 5,000ft. Snow levels rise=20
from 4000 to 5000ft over the WA Cascades Wednesday through=20
Thursday. By Friday, snow levels approach 6,000ft by Friday in
western WA. WPC probabilities for >4" is high (>70%) around Stevens
Pass, but lighter accumulations around Snoqualmie are anticipated
at this moment given the higher snow levels.

...Northern & Central Plains...
Days 2-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a
nearby 850mb front to support periods of snow from the northern
High Plains on south in the the central High Plains. Snow is not
expected to be overly heavy, although the Black Hills through
orographic lifting may be able to see snowfall amounts surpass 6".
This is supported in WPC probabilities which show moderate-to-high
chances (50-70%) for >4" of snow in the Black Hills, and low
chances (10-30%) in their peaks for >8". Elsewhere, from eastern MT
on south and east through the Missouri River Valley, most snowfall accumulations are likely to range between 1-3". Some hazardous
travel is possible, especially where roads temperatures are at or
below freezing in wake of the recent extreme cold.


...Southern Appalachians & Mid-Atlantic...
Days 3-3.5...

...Confidence In Impactful Snowfall Increasing For the Southern=20
Appalachians and Southern Mid-Atlantic...

To say there remains a large amount of model spread in the
potential winter storm beyond Day 3 would be an understatement. In
the past 24 hours, ensemble guidance have flipped camps to where
the GEFS are the snowier members, CMCE are more in the middle, and
the EC-EPS are trending less snowy. It is worth noting that AI=20
ensemble membership are not as snowy as the GEFS, but show a little
more snow than the EC-EPS, making this an interesting test in how=20
the AI ensemble membership performs.=20

Regarding the setup-- WPC Cluster Analysis shows this potential=20
winter storm comes down to several factors: 1) strength of the=20
emerging Great Lakes shortwave trough. 2) speed of the shortwave=20
trough. 3) tilt/amplitude of the shortwave trough as it tracks=20
east. 4) Confluence strength near Nova Scotia. They all work=20
together in an intricate dance that makes for difficulties in=20
modeling. A stronger/slower shortwave can buy time for confluence=20
over New England and Nova Scotia to weaken, giving the shortwave=20
more time to amplify, and allow for closer storm tracks to the=20
coast that bring heavy snow as far west as the I-95 corridor (some=20
GEFS members and some CMCE members). Where the shortwave is=20
stronger but progressive, heavier snowfall occurs but largely=20
closer to the coast and as far west as the NC Piedmont (CMCE=20
members, UK ensembles, split EC/GEFS members). If the shortwave=20
trough is more progressive and cannot separate itself from the=20
larger TPV to the east there is less amplification, it results in=20
a flatter and more positively/tilted shortwave trough, and thus the storm remains largely out at sea (EPS, EC-AIFS ensembles, some GEFS/CMCE
members). It is worth noting that, while the EC-AIFS has largely=20
performed well inside of 5 days much of the winter season, the EC-=20
AIFS and ECMWF did suppress the track of the most recent winter=20
storm too much ~4-5 days out before correcting northward inside of=20
72 hours out.

This setup is highly timing dependent; from the primary shortwave
trough currently east of Hudson Bay, to the interaction/spacing of
the 500mb cyclonic gyres in southeast Canada and south of Iceland
that promote the confluence ahead of the potential storm, to the=20
incoming Pacific shortwaves that track into western Canada and
adjust the strength/position of the western North America ridge.=20
There remain a host of embedded shortwaves that will work together=20
to create a complex storm evolution off the East Coast. Whatever=20
the current model solutions show beyond 72 hours out is unlikely to
be the final product. Expect additional model changes in the=20
coming days. If there is one thing that has increased in confidence
in the past 24 hours, it is the opportunity for coastal flooding=20
and beach erosion along the Mid-Atlantic coast. Please refer to our
"What We know, What We Don't Know" social media post for=20
additional information.

The one thing they do agree on is this upper trough tracks through
the OH Valley Friday afternoon with sufficient PVA and 850-500mb=20
mean layer moisture to support snow from central KY to the southern Appalachians through Friday evening. WPC probabilities do
show increasing chances for at least minor accumulations >2" over
KY and northeast TN, while there are low-chances (10-30%) for
snowfall totals >4" through early Saturday morning in the TN/NC
Smokeys and Blue Ridge of NC. Residents and those traveling to the
Carolinas on north up the East Coast will want to continue=20
following the forecasts from WPC and your local NWS WFO for the=20
latest regarding this potential winter storm.=20


The probability for significant icing is less than 10 percent.


Mullinax





...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!54SB-pOI55Au96P5L94fHwqMmZ5LkWpzYAasipw8QCoDB= HpKat7rnUR9CGCuvaNDYBiVEtFlpNZAFxNTxzAKGVc0XKY$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 272012
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
312 PM EST Tue Jan 27 2026

Valid 00Z Wed Jan 28 2026 - 00Z Sat Jan 31 2026


...Great Lakes...
Days 1-3...

The seemingly endless cyclonic flow that has kept the LES machine=20
cranking over snow belts of the Great Lakes looks to continue
through the remainder of the work-week. Frigid 850mb temperatures=20
will persist with temperatures around -18 to -24C, which are below
the 10th climatological percentile. According to GLERL, Lake Erie=20
is essentially ice covered, so available moisture will be limited=20
there while Lakes Superior and Ontario remain largely open. W-NWrly
low-level winds will continue through Wednesday before the approach
of a sharp 500mb shortwave pivots through and shifts winds more out
of the N-NNW by Thursday. Northerly flow continues Friday as high
pressure builds in over the Northern Plains. 72-hour WPC
probabilities depict high chances (>70%) for snowfall totals >4"
over the northern tier of the Michigan U.P. and down wind of Lake=20
Ontario to the south of an over the Tug Hill. The area with the=20
best odds of seeing over a foot of snow over the next few days are=20
near the Oswego, NY area where WPC probabilities for over a foot of
snow are in the moderate range of probabilities (40-60%).=20


...Cascades & Olympics...
Days 1-3...

A series of storm systems tracking into the Gulf of Alaska will
direct rounds of moisture and WAA at western WA through the
remainder of the week. Strong upslope flow should support locally
heavy snowfall totals as low as 4,000ft, but most heavy snow will=20
reside in the more remote areas above 5,000ft. Snow levels rise=20
from 4000 to 5000ft over the WA Cascades Wednesday through=20
Thursday. By Friday, snow levels approach 6,000ft by Friday in
western WA. WPC probabilities for >4" is high (>70%) around Stevens
Pass, but lighter accumulations around Snoqualmie are anticipated
at this moment given the higher snow levels.

...Northern & Central Plains...
Days 2-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a
nearby 850mb front to support periods of snow from the northern
High Plains on south in the the central High Plains. Snow is not
expected to be overly heavy, although the Black Hills through
orographic lifting may be able to see snowfall amounts surpass 6".
This is supported in WPC probabilities which show moderate-to-high
chances (50-70%) for >4" of snow in the Black Hills, and low
chances (10-30%) in their peaks for >8". Elsewhere, from eastern MT
on south and east through the Missouri River Valley, most snowfall accumulations are likely to range between 1-3". Some hazardous
travel is possible, especially where roads temperatures are at or
below freezing in wake of the recent extreme cold.


...Southern Appalachians & Mid-Atlantic...
Days 3-3.5...

...Confidence In Impactful Snowfall Increasing For the Southern=20
Appalachians and Southern Mid-Atlantic...

To say there remains a large amount of model spread in the
potential winter storm beyond Day 3 would be an understatement. In
the past 24 hours, ensemble guidance have flipped camps to where
the GEFS are the snowier members, CMCE are more in the middle, and
the EC-EPS are trending less snowy. It is worth noting that AI=20
ensemble membership are not as snowy as the GEFS, but show a little
more snow than the EC-EPS, making this an interesting test in how=20
the AI ensemble membership performs.=20

Regarding the setup-- WPC Cluster Analysis shows this potential=20
winter storm comes down to several factors: 1) strength of the=20
emerging Great Lakes shortwave trough. 2) speed of the shortwave=20
trough. 3) tilt/amplitude of the shortwave trough as it tracks=20
east. 4) Confluence strength near Nova Scotia. They all work=20
together in an intricate dance that makes for difficulties in=20
modeling. A stronger/slower shortwave can buy time for confluence=20
over New England and Nova Scotia to weaken, giving the shortwave=20
more time to amplify, and allow for closer storm tracks to the=20
coast that bring heavy snow as far west as the I-95 corridor (some=20
GEFS members and some CMCE members). Where the shortwave is=20
stronger but progressive, heavier snowfall occurs but largely=20
closer to the coast and as far west as the NC Piedmont (CMCE=20
members, UK ensembles, split EC/GEFS members). If the shortwave=20
trough is more progressive and cannot separate itself from the=20
larger TPV to the east there is less amplification, it results in=20
a flatter and more positively/tilted shortwave trough, and thus the
storm remains largely out at sea (EPS, EC-AIFS ensembles, some=20
GEFS/CMCE members). It is worth noting that, while the EC-AIFS has=20
largely performed well inside of 5 days much of the winter season,=20
the EC- AIFS and ECMWF did suppress the track of the most recent=20
winter storm too much ~4-5 days out before correcting northward=20
inside of 72 hours out.

This setup is highly timing dependent; from the primary shortwave
trough currently east of Hudson Bay, to the interaction/spacing of
the 500mb cyclonic gyres in southeast Canada and south of Iceland
that promote the confluence ahead of the potential storm, to the=20
incoming Pacific shortwaves that track into western Canada and
adjust the strength/position of the western North America ridge.=20
There remain a host of embedded shortwaves that will work together=20
to create a complex storm evolution off the East Coast. Whatever=20
the current model solutions show beyond 72 hours out is unlikely to
be the final product. Expect additional model changes in the=20
coming days. If there is one thing that has increased in confidence
in the past 24 hours, it is the opportunity for coastal flooding=20
and beach erosion along the Mid-Atlantic coast. Please refer to our
"What We know, What We Don't Know" social media post for=20
additional information.

The one thing they do agree on is this upper trough tracks through
the OH Valley Friday afternoon with sufficient PVA and 850-500mb=20
mean layer moisture to support snow from central KY to the southern Appalachians through Friday evening. WPC probabilities do
show increasing chances for at least minor accumulations >2" over
KY and northeast TN, while there are low-chances (10-30%) for
snowfall totals >4" through early Saturday morning in the TN/NC
Smokeys and Blue Ridge of NC. Residents and those traveling to the
Carolinas on north up the East Coast will want to continue=20
following the forecasts from WPC and your local NWS WFO for the=20
latest regarding this potential winter storm.=20


The probability for significant icing is less than 10 percent.


Mullinax






...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!6n-iHJKs776ZdQQmter1T3bY9tYWwGaL_csVXzv1NZMbv= Z1KeGyQSUWbB1TKYcgb1-m6K7MWiSPxJKNPHtV9eyKYDFI$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 280759
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
259 AM EST Wed Jan 28 2026

Valid 12Z Wed Jan 28 2026 - 12Z Sat Jan 31 2026


...Great Lakes...
Days 1-3...

The seemingly endless cyclonic flow that has kept the LES machine=20
cranking over snow belts of the Great Lakes looks to continue
through the remainder of the work-week. Frigid 850mb temperatures=20
will persist with temperatures around -18 to -24C, which are below
the 10th climatological percentile. According to GLERL, Lake Erie=20
is essentially ice covered, so available moisture will be limited=20
there while Lakes Superior and Ontario remain largely open. W-NWrly
low-level winds will continue today before the approach of a sharp
500mb shortwave pivots through and shifts winds more out of the=20
N-NNW by Thursday. Northerly flow continues Friday as high pressure
builds in over the Northern Plains. This northerly flow supports
the most likely area of heavy snow on Day 3 to be down wind of Lake
Michigan, potentially into the Chicago metro. 72-hour WPC=20
probabilities depict high chances (>70%) for snowfall totals >8"=20
over the eastern shores of Lake Superior in the Michigan U.P. and=20
down wind of Lake Ontario to the south of an over the Tug Hill. The
area with the best odds of seeing over a foot of additional snow=20
(most on Day 1) over the next few days are near the Oswego, NY area
where WPC probabilities for over a foot of snow are 10-20%. Day 3
probabilities down wind of Lake Michigan current depict moderate
probabilities 40-50% for at least 4" across the southwest shores of
Lake Michigan.


...Cascades & Olympics...
Days 1-3...

A series of storm systems tracking into the Gulf of Alaska will
direct rounds of moisture and WAA at western WA through the
remainder of the week. Strong upslope flow should support locally
heavy snowfall totals as low as 4,000ft, but most heavy snow will=20
reside in the more remote areas above 5,000ft. Snow levels rise=20
from 4000 to 5000ft over the WA Cascades Wednesday through=20
Thursday. By Friday, snow levels approach 6,000ft by Friday in
western WA. WPC probabilities for >4" is moderate (40-70%) around=20
Stevens Pass, but lighter accumulations around Snoqualmie are=20
anticipated at this moment given the higher snow levels.

...Northern & Central Plains...
Days 2-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a
nearby 850mb front to support periods of snow from the northern
High Plains on south in the the central High Plains. Snow is not
expected to be overly heavy, although the Black Hills through
orographic lifting may be able to see snowfall amounts surpass 6".
This is supported in WPC probabilities which show moderate-to-high
chances (50-70%) for >4" of snow in the Black Hills, and low
chances (10-30%) in their peaks for >8". Elsewhere, from eastern MT
on south and east through the Missouri River Valley, most snowfall accumulations are likely to range between 1-3". Some hazardous
travel is possible, especially where roads temperatures are at or
below freezing in wake of the recent extreme cold.


...Southern Appalachians & Mid-Atlantic...
Days 3...

...Confidence In Impactful Snowfall Increasing For the Southern=20
Appalachians and Southern Mid-Atlantic; Key Messages are linked at
the bottom of the discussion...

To say there remains a large amount of model spread in the
potential winter storm beyond Day 3 would be an understatement. In
the past 36-24 hours, ensemble guidance have flipped camps to=20
where the GEFS are the snowier members, CMCE are more in the=20
middle, and the EC-EPS are less snowy. It is worth noting that AI=20
ensemble membership are not as snowy as the GEFS, but show a little
more snow than the EC-EPS, making this an interesting test in how=20
the AI ensemble membership performs. However, within this overall
"cloud" of uncertainty, guidance is beginning to hone in on higher
chances for impactful snowfall across the Carolinas and southern
Virginia by the end of the Day 3 timeframe.

Regarding the setup-- WPC Cluster Analysis shows this potential=20
winter storm comes down to several factors: 1) strength of the=20
emerging Great Lakes shortwave trough. 2) speed of the shortwave=20
trough. 3) tilt/amplitude of the shortwave trough as it tracks=20
east. 4) Confluence strength near Nova Scotia. They all work=20
together in an intricate dance that makes for difficulties in=20
modeling. A stronger/slower shortwave can buy time for confluence=20
over New England and Nova Scotia to weaken, giving the shortwave=20
more time to amplify, and allow for closer storm tracks to the=20
coast that bring heavy snow as far west as the I-95 corridor (some=20
GEFS members and some CMCE members). Where the shortwave is=20
stronger but progressive, heavier snowfall occurs but largely=20
closer to the coast and as far west as the NC Piedmont (CMCE=20
members, UK ensembles, split EC/GEFS members). If the shortwave=20
trough is more progressive and cannot separate itself from the=20
larger TPV to the east there is less amplification, it results in=20
a flatter and more positively/tilted shortwave trough, and thus the
storm remains largely out at sea (EPS, EC-AIFS ensembles, some=20
GEFS/CMCE members). It is worth noting that, while the EC-AIFS has=20
largely performed well inside of 5 days much of the winter season,=20
the EC- AIFS and ECMWF did suppress the track of the most recent=20
winter storm too much ~4-5 days out before correcting northward=20
inside of 72 hours out.

In terms of storm analogs, this upper level setup and TPV=20
interaction does not appear like a common scenario to get a deep=20
upper low rapidly deepening near the Southeast/Mid- Atlantic. Most=20
analog matches seem to get towards the closed upper low in=20
different ways or suppress the system altogether leaving little in=20
terms of precipitation. However, the 12z Tuesday CIPS Analogs
(GFS-based) highlighted the significant winter storm of March 1980
as an interesting top match. This storm produced very heavy=20
snowfall across VA and eastern NC and can simply show the ceiling=20
this type of setup can have. Like what was previously mentioned,=20
other limited analogs are suppressed and show the very low floor=20
that is still possible. All ensemble systems GEFS/CMCE/EPS/EC-
AIFS/AIGEFS show this large spread as well.

Back to the current forecast. This setup is highly timing=20
dependent; from the primary shortwave trough currently east of=20
Hudson Bay, to the interaction/spacing of the 500mb cyclonic gyres=20
in southeast Canada and south of Iceland that promote the=20
confluence ahead of the potential storm, to the incoming Pacific=20
shortwaves that track into western Canada and adjust the=20
strength/position of the western North America ridge. There remain=20
a host of embedded shortwaves that will work together to create a=20
complex storm evolution off the East Coast. Whatever the current=20
model solutions show beyond 72 hours out is unlikely to be the=20
final product. Expect additional model changes in the coming days.=20
If there is an additional aspect to this storm that has increased=20
in confidence in the past 24 hours, it is the opportunity for=20
coastal flooding and beach erosion along the Mid-Atlantic coast.

The one thing they do agree on is this upper trough tracks through
the OH Valley Friday afternoon with sufficient PVA and 850-500mb=20
mean layer moisture to support snow from central KY to the southern Appalachians through Friday night. Then, the closing off of a 850mb
low seems plausible across the southern Appalachians Saturday=20
morning, which should help increase lift into the Carolina=20
Piedmont. WPC probabilities do show increasing chances for at least
minor accumulations >4" over eastern KY and northeast TN, while=20
there are low- chances (10-30%) for snowfall totals >4" through=20
early Saturday morning in the TN/NC Smokeys and Blue Ridge of NC.=20 Probabilities then begin to increase to 30-50% across central NC by
12z Saturday. Most snowfall associated with this system is=20
expected to occur after 12z Saturday, so be sure to check back for=20
the latest forecast as it enters the short range over the next few=20
days. Residents and those traveling to the Carolinas on north up=20
the East Coast will want to continue following the forecasts from=20
WPC and your local NWS WFO for the latest regarding this potential=20
winter storm.



The probability for significant icing is less than 10 percent.


Snell/Mullinax





...Extreme Cold (1) & Winter Storm (2) Key Messages are in effect.
Please see current Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!77Xu4C4_ejyNPuXJ8gEnnObVKlTXBwG2suWpfLuKOVzPG= BINbP5K5P9TIQ5cCqP2wLS3M1N8_NCpSzZOgD1PInZ4pUQ$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!77Xu4C4_ejyNPuXJ8gEnnObVKlTXBwG2suWpfLuKOVzPG= BINbP5K5P9TIQ5cCqP2wLS3M1N8_NCpSzZOgD1PtfsLqMU$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 280807
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
307 AM EST Wed Jan 28 2026

Valid 12Z Wed Jan 28 2026 - 12Z Sat Jan 31 2026


...Great Lakes...
Days 1-3...

The seemingly endless cyclonic flow that has kept the LES machine=20
cranking over snow belts of the Great Lakes looks to continue
through the remainder of the work-week. Frigid 850mb temperatures=20
will persist with temperatures around -18 to -24C, which are below
the 10th climatological percentile. According to GLERL, Lake Erie=20
is essentially ice covered, so available moisture will be limited=20
there while Lakes Superior and Ontario remain largely open. W-NWrly
low-level winds will continue today before the approach of a sharp
500mb shortwave pivots through and shifts winds more out of the=20
N-NNW by Thursday. Northerly flow continues Friday as high pressure
builds in over the Northern Plains. This northerly flow supports
the most likely area of heavy snow on Day 3 to be down wind of Lake
Michigan, potentially into the Chicago metro. 72-hour WPC=20
probabilities depict high chances (>70%) for snowfall totals >8"=20
over the eastern shores of Lake Superior in the Michigan U.P. and=20
down wind of Lake Ontario to the south of an over the Tug Hill. The
area with the best odds of seeing over a foot of additional snow=20
(most on Day 1) over the next few days are near the Oswego, NY area
where WPC probabilities for over a foot of snow are 10-20%. Day 3
probabilities down wind of Lake Michigan current depict moderate
probabilities 40-50% for at least 4" across the southwest shores of
Lake Michigan.


...Cascades & Olympics...
Days 1-3...

A series of storm systems tracking into the Gulf of Alaska will
direct rounds of moisture and WAA at western WA through the
remainder of the week. Strong upslope flow should support locally
heavy snowfall totals as low as 4,000ft, but most heavy snow will=20
reside in the more remote areas above 5,000ft. Snow levels rise=20
from 4000 to 5000ft over the WA Cascades Wednesday through=20
Thursday. By Friday, snow levels approach 6,000ft by Friday in
western WA. WPC probabilities for >4" is moderate (40-70%) around=20
Stevens Pass, but lighter accumulations around Snoqualmie are=20
anticipated at this moment given the higher snow levels.

...Northern & Central Plains...
Days 2-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a
nearby 850mb front to support periods of snow from the northern
High Plains on south in the the central High Plains. Snow is not
expected to be overly heavy, although the Black Hills through
orographic lifting may be able to see snowfall amounts surpass 6".
This is supported in WPC probabilities which show moderate-to-high
chances (50-70%) for >4" of snow in the Black Hills, and low
chances (10-30%) in their peaks for >8". Elsewhere, from eastern MT
on south and east through the Missouri River Valley, most snowfall accumulations are likely to range between 1-3". Some hazardous
travel is possible, especially where roads temperatures are at or
below freezing in wake of the recent extreme cold.


...Southern Appalachians & Mid-Atlantic...
Days 3...

...Confidence In Impactful Snowfall Increasing For the Southern=20
Appalachians and Southern Mid-Atlantic; Key Messages are linked at
the bottom of the discussion...

To say there remains a large amount of model spread in the
potential winter storm beyond Day 3 would be an understatement. In
the past 36-24 hours, ensemble guidance have flipped camps to=20
where the GEFS are the snowier members, CMCE are more in the=20
middle, and the EC-EPS are less snowy. It is worth noting that AI=20
ensemble membership are not as snowy as the GEFS, but show a little
more snow than the EC-EPS, making this an interesting test in how=20
the AI ensemble membership performs. However, within this overall
"cloud" of uncertainty, guidance is beginning to hone in on higher
chances for impactful snowfall across the Carolinas and southern
Virginia by the end of the Day 3 timeframe.

Regarding the setup-- WPC Cluster Analysis shows this potential=20
winter storm comes down to several factors: 1) strength of the=20
emerging Great Lakes shortwave trough. 2) speed of the shortwave=20
trough. 3) tilt/amplitude of the shortwave trough as it tracks=20
east. 4) Confluence strength near Nova Scotia. They all work=20
together in an intricate dance that makes for difficulties in=20
modeling. A stronger/slower shortwave can buy time for confluence=20
over New England and Nova Scotia to weaken, giving the shortwave=20
more time to amplify, and allow for closer storm tracks to the=20
coast that bring heavy snow as far west as the I-95 corridor (some=20
GEFS members and some CMCE members). Where the shortwave is=20
stronger but progressive, heavier snowfall occurs but largely=20
closer to the coast and as far west as the NC Piedmont (CMCE=20
members, UK ensembles, split EC/GEFS members). If the shortwave=20
trough is more progressive and cannot separate itself from the=20
larger TPV to the east there is less amplification, it results in=20
a flatter and more positively/tilted shortwave trough, and thus the
storm remains largely out at sea (EPS, EC-AIFS ensembles, some=20
GEFS/CMCE members). It is worth noting that, while the EC-AIFS has=20
largely performed well inside of 5 days much of the winter season,=20
the EC- AIFS and ECMWF did suppress the track of the most recent=20
winter storm too much ~4-5 days out before correcting northward=20
inside of 72 hours out.

In terms of storm analogs, this upper level setup and TPV=20
interaction does not appear like a common scenario to get a deep=20
upper low rapidly strengthening near the Southeast/Mid- Atlantic.=20
Most analog matches seem to get towards the closed upper low in=20
different ways or suppress the system altogether leaving little in=20
terms of precipitation. However, the 12z Tuesday CIPS Analogs (GFS-
based) highlighted the significant winter storm of March 1980 as=20
an interesting top match. This storm produced very heavy snowfall=20
across VA and eastern NC and can simply show the ceiling this type=20
of setup can have. Like what was previously mentioned, other=20
limited analogs are suppressed and show the very low floor that is=20
still possible. All ensemble systems GEFS/CMCE/EPS/EC- AIFS/AIGEFS=20
show this large spread as well.

Back to the current forecast. This setup is highly timing=20
dependent; from the primary shortwave trough currently east of=20
Hudson Bay, to the interaction/spacing of the 500mb cyclonic gyres=20
in southeast Canada and south of Iceland that promote the=20
confluence ahead of the potential storm, to the incoming Pacific=20
shortwaves that track into western Canada and adjust the=20
strength/position of the western North America ridge. There remain=20
a host of embedded shortwaves that will work together to create a=20
complex storm evolution off the East Coast. Whatever the current=20
model solutions show beyond 72 hours out is unlikely to be the=20
final product. Expect additional model changes in the coming days.=20
If there is an additional aspect to this storm that has increased=20
in confidence in the past 24 hours, it is the opportunity for=20
coastal flooding and beach erosion along the Mid-Atlantic coast.

The one thing they do agree on is this upper trough tracks through
the OH Valley Friday afternoon with sufficient PVA and 850-500mb=20
mean layer moisture to support snow from central KY to the southern Appalachians through Friday night. Then, the closing off of a 850mb
low seems plausible across the southern Appalachians Saturday=20
morning, which should help increase lift into the Carolina=20
Piedmont. WPC probabilities do show increasing chances for at least
minor accumulations >4" over eastern KY and northeast TN, while=20
there are low- chances (10-30%) for snowfall totals >4" through=20
early Saturday morning in the TN/NC Smokeys and Blue Ridge of NC.=20 Probabilities then begin to increase to 30-50% across central NC by
12z Saturday. Most snowfall associated with this system is=20
expected to occur after 12z Saturday, so be sure to check back for=20
the latest forecast as it enters the short range over the next few=20
days. Residents and those traveling to the Carolinas on north up=20
the East Coast will want to continue following the forecasts from=20
WPC and your local NWS WFO for the latest regarding this potential=20
winter storm.



The probability for significant icing is less than 10 percent.


Snell/Mullinax





...Extreme Cold (1) & Winter Storm (2) Key Messages are in effect.
Please see current Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!8TANDUoTZL_uMahppCEn7lOgTUVSMGtUDbz_RXsEfHhME= ATsMx_veotJcy8MV2KCSOFvGpr4l7xjG6CeUg9vKvyvDL8$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!8TANDUoTZL_uMahppCEn7lOgTUVSMGtUDbz_RXsEfHhME= ATsMx_veotJcy8MV2KCSOFvGpr4l7xjG6CeUg9vTm6w4sc$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 281947
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
247 PM EST Wed Jan 28 2026

Valid 00Z Thu Jan 29 2026 - 00Z Sun Feb 01 2026


...Great Lakes...
Days 1-3...

The seemingly endless cyclonic flow that has kept the LES machine=20
cranking over snow belts of the Great Lakes looks to continue
through the remainder of the work-week. Frigid 850mb temperatures=20
will persist with temperatures around -18 to -24C, which are below
the 10th climatological percentile. According to GLERL, Lake Erie=20
is effectively ice covered, so available moisture will be limited=20
there while Lakes Superior and Ontario remain largely open. W-NWrly
low-level winds will continue today before the approach of a sharp
500mb shortwave passes through and shifts winds more out of the=20
north by late Thursday. Northerly flow continues Friday with=20
shifting NNE flow possible into Saturday, which could place the=20
Chicagoland area under the presence of a Lake Michigan single-=20
banded LES streamer late Friday into Saturday. 72-hour WPC=20
probabilities depict high chances (>70%) for snowfall totals >8"=20
over the eastern shores of Lake Superior in the Michigan U.P. and=20
down wind of Lake Ontario to the south of an over the Tug Hill. The
area with the best odds of seeing over a foot of additional snow=20
(most on Day 1) over the next few days are near the Oswego, NY area
where WPC probabilities for over a foot of snow are 10-20%. Day 3=20 probabilities down wind of Lake Michigan current depict moderate-=20
to-high chances (40-70%) for at least 4" along the southern shores
of Lake Michigan.


...Cascades & Olympics...
Days 1-3...

A series of storm systems tracking into the Gulf of Alaska will
direct rounds of moisture and WAA at western WA through the
remainder of the week. Strong upslope flow should support locally
heavy snowfall totals as low as 4,000ft, but most heavy snow will=20
reside in the more remote areas above 5,000ft. Snow levels rise=20
from 4000 to 5000ft over the WA Cascades Wednesday through=20
Thursday. By Friday, snow levels approach 6,000ft by Friday in
western WA. WPC probabilities for >4" is moderate (40-60%) around=20
Stevens Pass, but lighter accumulations around Snoqualmie are=20
anticipated at this moment given the higher snow levels.

...Northern & Central Plains...
Days 1-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a
nearby 850mb front to support periods of snow from the northern
High Plains on south in the the central High Plains. Guidance is
even keying in on an area of 700mb FGEN over the Black Hills on
south into the Nebraska Sand Hills that could support moderate snow
bands Friday morning. Snow is not expected to be overly heavy,=20
although the Black Hills through orographic lifting and some=20
localized banding may be able to see snowfall amounts surpass 6".=20
This is supported in WPC probabilities which show moderate-to-high=20
chances (50-70%) for >4" of snow in the Black Hills, and low-to-=20
moderate chances (20-50%) in their peaks for >8". Elsewhere, from=20
eastern MT on south and east through the Missouri River Valley,=20
most snowfall accumulations are likely to range between 1-3". Even=20
some localized instances of freezing rain in the northern High=20
Plains on late Friday into Saturday given the favorable overrunning
from WAA at low-mid levels and sub-freezing surface temps. Some=20
hazardous travel is possible, especially where roads temperatures=20
are at or below freezing in wake of the recent extreme cold.


...Southern Appalachians & Mid-Atlantic...
Days 2.5-3.5...

...Confidence growing for a major winter storm & heavy snowfall=20
across the southern Mid-Atlantic...

WPC cluster analysis continues to show the primary driving factors
in the development of this impending winter storm are the
strength/speed/tilt of the approaching shortwave trough in the
Great Lakes and the spacing between the trough and the TPV over
southeast Canada. The meteorology is supportive of a significant
winter storm from the southern Appalachians and Carolinas on north
and east through the VA Tidewater. Just about all ensemble=20
guidance now show the shortwave trough over the OH Valley Friday=20
evening deepening into a powerful and highly anomalous closed low=20
that tracks into the southern Appalachians Saturday evening. By the
end of this forecast period (00Z Sun) the ECMWF 500mb heights are=20 approaching record low levels over the FL Panhandle for late Jan-=20
early Feb. As the 500mb low approaches, exceptional PVA and WAA=20
over the Mid-Atlantic coast will spawn low pressure along the=20
strengthening coastal front. This aligns well across the 12Z GFS=20
and 06Z ECMWF which show increasing 700mb Q-vector convergence near
the NC Outer Banks that fosters healthy mid-level ascent. This=20
aligns favorably beneath the diffluent left-exit region of a=20

100kt 500mb jet streak located a the base of the closed 500mb low.

As the 700mb low tracks towards the Cape Fear region Saturday=20
night, the axis of heaviest snowfall will reside on the 700mb low's
northern and western flank.

Where guidance still disagrees is the progression of the storm and
its proximity to the coast. The tilt of the 500mb trough and closed
low plays a key role in this, as it maximizes vertical ascent and=20
draws moisture farther north if the system takes on a negative=20
tilt. The EC-AIFS ensemble mean has been gradually decreasing QPF=20
largely because the negative tilt takes longer to occur and there=20
is less time for the developing 850mb low to tap into moisture off
the Gulf Stream. Most guidance holds off on a negative until=20
Sunday, which is why there is a "gap" in the snowfall from northern
VA on up I-95 to the NYC metro area, but heavy snow becomes=20
possible over southeast New England by Sunday thanks to the region=20
sticking out eastward into the Atlantic. Note the 12Z GEFS, 06Z=20
EPS, and 12Z EC-AIFS ensembles are still showing changes in its=20
mean inside of 72 hours, so exact amounts and the expanse of the=20
snow shield are still likely to change. In addition, unlike the=20
last winter storm, wind will have a more profound impact up and=20
down the Eastern Seaboard. The 00Z ECMWF EFI shows wind speeds that
are topping 0.8 from the MA Capes on south along the NC Coast.=20
These anomalous winds also align with climatologically significant=20
snowfall potential along the coasts, indicating the concern for=20
blizzard conditions in affected coastal areas.=20

CIPS Analogs (GFS-based) continue to suggest this storm's=20
potential ceiling could be exceptional, particularly in the=20
Carolinas. CIPS is keying in on several past major winter storms=20
that featured similar 300mb & 500mb evolutions to what the GFS is=20
showing, just 100-200 miles farther south and east from where those
events unfolded. While the CIPS analogs are analyzing the GFS, the
differences in the GFS versus the ECMWF are not all that different
when it comes to the meteorology involved: powerful closed upper=20
low, healthy upper-level divergence over a strengthening coastal=20
front, and tapping into Atlantic moisture revolving around the=20
closed 700mb low. In summary-- ensembles are beginning to identify
the floor of this winter storm (disruptive winter storm in the=20
southern Mid-Atlantic) but based on some of the analogs, there is a
potentially more significant-ceiling that could be achieved in the
Carolinas should guidance consolidate on a slower and more intense
winter storm. Given it is 72 hours out, there remains some caution
when it comes to expected snowfall totals.

WPC probabilities through Saturday night currently show moderate-
to-high chances (50-80%) for snowfall totals >4" from the NC=20
Piedmont on east to eastern NC and southeast VA. It is worth noting
some higher end solutions are present with low-to-moderate chances
(30-50%) for snowfall totals >8" over central NC through 06Z Sunday.
The Probabilistic Winter Storm Severity Index (WSSI-P) is=20
depicting >50% chances for Moderate Impacts from the SC/GA border=20
on north and east to lower DelMarVa Peninsula. The Major Impacts=20
are >50% in the eastern Charlotte metro, the NC Piedmont right=20
along NC's I-95 corridor, and into southeast VA. These elevated
WSSI-P Major probabilities highlight the concern for a highly=20
impactful winter storm late Saturday and into Sunday for the=20
southern Mid-Atlantic with more disruptions to travel and=20
infrastructure anticipated. Residents and those traveling to the=20
Carolinas on north up the East Coast will want to continue=20
following the forecasts from WPC and your local NWS WFO for the=20
latest regarding this potential winter storm.


The probability for significant icing is less than 10 percent.


Mullinax




...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!5Cj4msK-dv0Kb7_AGDSgu7ZDdEOXNYFYPw2QvpYtmFd6N= CNtmp24XMTtrscfs6fvs4sGCn1UXXix-0GDZBAeT4q-EBM$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!5Cj4msK-dv0Kb7_AGDSgu7ZDdEOXNYFYPw2QvpYtmFd6N= CNtmp24XMTtrscfs6fvs4sGCn1UXXix-0GDZBAeMWJe7mA$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 290746
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
246 AM EST Thu Jan 29 2026

Valid 12Z Thu Jan 29 2026 - 12Z Sun Feb 01 2026


...Great Lakes...
Days 1-2...

Continued cyclonic flow will continue to favor lake effect snow=20
across the Great Lakes for another couple of days. Frigid 850mb=20
temperatures will persist with temperatures around -18 to=20
-24C, which are below the 10th climatological percentile. WNW flow
will turn more northerly (or NNE) as the sharp 500mb shortwave
passes through later today. On Friday, northerly flow continues
Friday with NNE flow possible into Chicagoland carrying a band
into the region overnight into Saturday. Most snow winds downs
late Saturday into early Sunday with a surface high overhead.
Single band off Lake Ontario will weaken later today but persist
through Friday.

For days 1-2, WPC probabilities for at least 6 inches of snow are

50% over parts of the Michigan U.P. and downwind of Lake Ontario=20

near Oswego, where over 10 inches is possible. Over Chicago, WPC=20 probabilities for at least 4 inches are not quite 30% but some CAM=20
guidance shows a farther westward push out of NW Indiana than=20
others.=20


...Cascades & Olympics...
Days 1-2...

A series of storm systems tracking into the Gulf of Alaska will=20
direct rounds of moisture and WAA at western WA through the=20
remainder of the week. Strong upslope flow should support locally=20
heavy snowfall totals above 5,000ft. Snow levels approach=20
6,000-6,500ft by Friday into Saturday in western WA as=20
precipitation ends.=20


...Northern & Central Plains...
Days 1-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a=20
nearby 850mb front to support periods of snow from the northern=20
High Plains on south in the the central High Plains. Guidance is=20
even keying in on an area of 700mb FGEN over the Black Hills on=20
south into the Nebraska Sand Hills that could support moderate snow
bands Friday morning. Snow is not expected to be overly heavy,=20
although the Black Hills through orographic lifting and some=20
localized banding may be able to see snowfall amounts surpass 6".=20
This is supported in WPC probabilities which show 60-80%=20
probabilities for >4" of snow in the Black Hills, and low-to-=20
moderate chances (20-50%) in their peaks for >8". Elsewhere, from=20
eastern MT on south and east through the Missouri River Valley,=20
most snowfall accumulations are likely to range between 1-3". Even=20
some localized instances of freezing rain in the northern High=20
Plains on late Friday into Saturday given the favorable overrunning
from WAA at low-mid levels and sub-freezing surface temps. Some=20
hazardous travel is possible, especially where roads temperatures=20
are likely below freezing in the wake of the recent extreme cold.


...Southern Appalachians & Mid-Atlantic...
Days 2-3...

...Confidence growing for a major winter storm & heavy snowfall=20
across the southern Mid-Atlantic...

Models continue to point to an anomalous and impactful event for=20
the southern Appalachians and especially southern Mid-Atlantic=20
states this weekend, aided by record cold into the=20
Southeast/Florida. Though the various models/ensembles have wavered
in their evolution and track of the system, nearly all show a=20
powerful ocean storm that will affect the southern Mid-Atlantic as=20 cyclogenesis ensues.=20

As a very deep 500mb low approaches the region, exceptional PVA=20
and WAA over the Mid-Atlantic coast will spawn low pressure along=20
the strengthening coastal front. Increasing 700mb Q-vector=20
convergence near the NC Outer Banks will foster healthy mid-level=20
ascent beneath the diffluent left-exit region of a >100kt 500mb jet
streak located at the base of the closed 500mb low. As the 700mb=20
low tracks towards the Cape Fear region Saturday night, the axis of
heaviest snowfall will reside on the 700mb low's northern and=20
western flank while surface low pressure explosively deepens into=20
the 970s mb by Sunday morning. Snow will likely fall heavily at=20
times over eastern NC late Saturday into early Sunday west of the=20
surface low as the mid-level upper low eventually catches up. In=20
addition, winds will increase which will create blowing and=20
drifting snow with possible blizzard conditions. Snow will also=20
expand northeastward up along the Mid- Atlantic coast into Long=20
Island and southern/southeastern New England but with a lot of=20
uncertainty in the expanse of the precipitation shield.

Through 12Z Sunday, WPC probabilities for at least 8 inches of=20
snow are >50% over the southern Appalachians, much of central to=20
eastern NC, as well as southern VA and northeastern SC. Within this
region, WPC probabilities for at least 12 inches of snow are >40%=20
over eastern NC. The footprint of impactful snowfall (>2" to the=20
south) extends into northeastern/eastern GA, through much of SC=20
(except for the Lowcountry where ptypes/thermals are more=20
uncertain), and as far north into the DelMarVa and southeastern NJ.


The Probabilistic Winter Storm Severity Index (WSSI-P) shows >50%=20
chances for Major impacts from the NC/SC border to southeastern VA.
These elevated WSSI-P Major probabilities indicate an unusual/rare
event is increasingly likely.=20


The probability for significant icing is less than 10 percent.


Fracasso/Mullinax


...Winter Storm Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!4CUOSQKzFnNbuP0ngRlzupRluDzSlOf6XOxWtVIaMamPu= jK5SigKJj5NkEGuj9rswLkOdYSJyPEWhVxQJ46-zwVAXj8$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!4CUOSQKzFnNbuP0ngRlzupRluDzSlOf6XOxWtVIaMamPu= jK5SigKJj5NkEGuj9rswLkOdYSJyPEWhVxQJ46-crIXiPo$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 292015
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
315 PM EST Thu Jan 29 2026

Valid 00Z Fri Jan 30 2026 - 00Z Mon Feb 02 2026


...Southern Appalachians, Mid-Atlantic, & Southern New England...=20
Days 1-3...

...A major winter storm is expected to produce heavy snowfall=20
across the southern Mid-Atlantic, blizzard conditions along the=20
Mid- Atlantic coasts, & potentially heavy snow in southern New=20
England...

Meteorological Overview...

An arctic air-mass anchored over the eastern U.S. will set the
stage for an amplifying shortwave trough over the OH Valley to
produce a major winter storm over the southern Appalachians and=20
southern Mid-Atlantic beginning Friday afternoon and continuing
into the weekend. Snow will begin as early as Friday morning=20
across the TN Valley and east to the southern/central Appalachians=20
due to low-level WAA, increasing PVA aloft, plus upslope=20
enhancement into the Appalachians. As the upper trough sharpens=20
over near the OH/MS Confluence, a robust >100kt 500mb jet streak=20
will place its divergent left-exit region over the southern Mid-=20
Atlantic and snow will envelop much of the Appalachians and=20
Piedmont of the Southeast come early Saturday morning.=20

By 12Z Saturday, most guidance is in agreement that the 500mb
shortwave takes on a more neutral tilt (oriented N-S) over the TN
Valley and becomes a closed low over GA. PVA becomes maximized=20
over the Southeast while a surface low spawns along a coastal=20
front east of the Carolinas. As the 850mb low deepens over northern
GA and heads east into SC, easterly 850mb theta-e advection will=20
direct low-level moisture around the 850mb low and support a band=20
of moderate-to-heavy snow from northern GA to central SC. Farther=20
north, the same tongue of 850mb theta-e is funneling along the=20
850mb front to the north of the 850mb low track from northern SC=20
on east through the heart of NC. This is where the deformation zone
is likely to form, pivoting over central NC and northern SC with=20
1-2"/hr snowfall rates likely. This band of heavy snow is likely to
ensue farther east into southeast VA, where 700mb FGEN is more=20
ideally placed to support strong vertical velocities within a fully
saturated DGZ. Similar to NC, look for intense bands of heavy snow
over southeast VA to form late Saturday afternoon and persist into
Saturday night. These bands of heavy snow in eastern NC and=20
southeast VA depict 700-500mb lapse rates >6.5C/km Saturday=20
afternoon and evening. It is here where not only are 2"/hr snowfall
rates achievable, but so is the likelihood for thundersnow. The
intense vertical velocities in eastern NC and southeast VA may
result in some subsidence in north-central NC and south-central VA.
Snowfall is still likely to reach warning criteria, but these
regions are potentially susceptible to lesser snowfall amounts as
they are caught between the influence of the strong upper-low to
the south, and the strengthening coastal low.

Speaking of the coastal low, along the coast VA/NC/SC coasts, not=20
only will the deformation zone of heavy snow pivot through, but the
explosive deepening of the storm east of Cape Hatteras will=20
support strong to potentially damaging wind gusts. Latest ECMWF=20
shows low pressure south of Hatteras is around 1007mb at 12Z=20
Saturday, then by 12Z Sunday is 972mb east of Hatteras, indicative=20
of rapid intensification. With strong high pressure to the west, a=20
strong isallobaric flow will develop in response, creating wind=20
gusts along the DelMarVa coast on south through the Outer Banks=20
that could approach hurricane-force at times. These coastal areas=20
overlap with the ECMWF EFI in >0.8 values for both snow and wind,=20
making these areas most susceptible to blizzard conditions. Not to=20
be ignored either, strong wind gusts atop the Smokeys and Blue=20
Ridge are likely to top 60 mph as well, resulting in possible=20
blizzard conditions in those higher elevations of the southern=20
Appalachians. Power outages are likely in some parts of the
southern Mid-Atlantic, particularly areas at risk for those
hurricane-force wind gusts along the VA/NC coast.

While there is still some uncertainty in storm track, most guidance
(including AIFS ensembles) have continued to trend lower in
snowfall amounts from northern VA on north and east along I-95 to=20
the Tri-state area. There remains a high degree of uncertainty over
southeast MA where the differences in the EPS-AIFS 75th and 25th=20
percentile snowfall outcomes south of Boston still are quite=20
striking. The locations that should still contend with periods of=20
snow are Martha's Vineyard and Nantucket given their closer=20
proximity to the snow shield.=20

Snowfall & Impacts...

WPC probabilities for the duration of the event show moderate-to-
high chances (50-80%) for snowfall totals >8" in the Blue
Ridge/Smokeys, west-central NC on east through northern SC,
southern NC, and along the Tidewater regions of VA/NC. It is
southeast VA, eastern NC, and southern NC that feature the highest
odds for snowfall totals >12" at 40-60%. Wilmington, NC has at
least a 50% chance of receiving >12" of snow. For context, dating=20
back to 1870, Wilmington, NC has only observed 3 instances where=20

12" of snowfall occurred: Feb 1896, Feb 1973, and Dec 1989.=20

The snowfall likely to occur across the Carolinas has a good=20
chance to be not just significant but historic and highly=20
disruptive, not just during the event, but for days after it is=20
long gone. WSSI shows an expansive area of Major Impacts=20
(considerable disruptions to daily life; dangerous to impossible=20
travel, widespread closures, disruptions to infrastructure) from=20
central SC (including Columbia, SC) through the eastern two-thirds=20
of NC (Charlotte/Raleigh- Durham). The WSSI-P shows low-to-
moderate chances (20-50%) for Extreme Impacts (per the WSSI=20
legend: extremely dangerous conditions, life saving actions may be
needed) in southern NC, including the I-95 corridor from=20
Fayetteville, NC to Florence, SC. Along the coast, WSSI shows Major
to locally Extreme conditions along VA Beach on south into the=20
northern OBX and along the north and east-facing shores facing the
Pamlico and Albemarle sounds, largely due the blizzard potential=20
and heavy snow. This speaks to the severity of this major winter=20
storm in the Carolinas. Lastly, with frigid temperatures in the=20
storm's wake on Sunday and lasting into Tuesday, the snow will not=20
melt much following the conclusion of the storm. Any melting that=20
occurs thanks to daytime heating is likely to cause refreezing on=20
untreated roads and surfaces. Residents in the Carolinas should=20
finish preparations as soon as possible, as road conditions will be
treacherous Saturday and into the first half of next week.

Elsewhere, travel disruptions are possible as far south and west as
the Atlanta metro area where the WSSI (as of this discussion's
issuance) shows Minor Impacts. Look for measurable snow to cause
hazardous travel as far west as the TN Valley and as far south as
Savannah where snowfall accumulations up to 1" is possible.
Moderate Impacts (hazardous travel and some infrastructure
impacts) are also forecast in Charleston, SC in the Smokeys/Blue=20
Ridge of western NC/TN, and as far north as the southern Richmond,=20
VA suburbs. Impacts are still unclear in southeast MA, but expect=20
blowing snow to cause reduced visibilities in the southeast MA=20
islands.=20


...Great Lakes...
Days 1-2...

Cyclonic flow will continue to favor lake effect snow across the=20
Great Lakes into the first half of the weekend. Frigid 850mb=20
temperatures will persist with temperatures around -18 to -24C,=20
which are below the 10th climatological percentile. WNW flow will=20
turn more northerly (even NNE for a time) as the sharp 500mb=20
shortwave passes over the Great Lakes tonight. On Friday, northerly
flow continues Friday with NNE flow possible into Chicagoland=20
carrying a LES band into the region overnight into Saturday.=20

Latest guidance has favored the heavier snow over far northwest=20
IN, although localized totals approaching 4" along the Lake Michigan
shores in Chicago are possible. Most snowfall winds downs late=20
Saturday into early Sunday as surface high pressure builds in overhead.
Single band off Lake Ontario will weaken starting this afternoon=20
but persist through Friday. For days 1-2, WPC probabilities for at=20
least 4 inches of snow are >50% over parts of the Michigan U.P. and
downwind of Lake Ontario near Oswego, where additional snowfall up
to 8" are possible.

...Northern Great Plains & Upper Midwest...
Days 1-3...

Two rounds of snow are expected; one this evening and into Friday
morning, then the other starting late Friday night and continuing
into the weekend. Weak 850-700mb WAA and FGEN will support light
snow over the western Dakotas and into the Nebraska Sand Hills
tonight and Friday AM. Snowfall totals are likely to range between
1-3" in these areas by the time snow concludes late Friday=20
morning, with the Black Hills sporting low chances (10-30%) for=20
snowfall total over 4". By Friday night, a Pacific shortwave trough
escorts Pacific moisture eastward into the Northern Plains=20
Saturday morning, then into the Upper Midwest Saturday evening into
Sunday. Patches of freezing rain in the northern High Plains on=20
late Friday into Saturday are expected given the favorable=20
overrunning from WAA at low-mid levels and sub-freezing surface=20
temps. Farther east, snow is the more likely precip type from the=20
Red River of the North on south to the Missouri Valley, then east=20
to the Mississippi river and MN Arrowhead. Snow totals are forecast
to range between 1-3" in these areas late Saturday into Sunday.=20
Some hazardous travel is possible, especially where roads=20
temperatures are likely below freezing in the wake of the recent=20
extreme cold.


Mullinax



...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!9uwfHTIrXu4nB5pX8IiYt7LWwCT8oOZLhh6Q6IBpUX5Qs= 3ag7Wrua_Ul_oXoc_41EI5uC8IA5fYogem_z21P6LZ1O9o$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!9uwfHTIrXu4nB5pX8IiYt7LWwCT8oOZLhh6Q6IBpUX5Qs= 3ag7Wrua_Ul_oXoc_41EI5uC8IA5fYogem_z21PLNrxWmE$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 300739
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
239 AM EST Fri Jan 30 2026

Valid 12Z Fri Jan 30 2026 - 12Z Mon Feb 02 2026


...Southern Appalachians, Mid-Atlantic, & Southern New England...=20
Days 1-3...

...A major winter storm is expected to produce heavy snowfall and=20
blizzard conditions across the southern Mid-Atlantic...

Meteorological Overview...

An arctic air mass anchored over the eastern U.S. will set the=20
stage for an amplifying shortwave trough over the OH Valley to=20
produce a major winter storm over the southern Appalachians and=20
southern Mid-Atlantic beginning later this afternoon and continuing
into the weekend. Snow over the TN Valley this morning will move=20
into the southern/central Appalachians this afternoon due to low-
level WAA, increasing PVA aloft, and upslope enhancement. As the=20
upper trough sharpens over/near the OH/MS Confluence, a robust=20

100kt 500mb jet streak will place its divergent left-exit region=20

over the southern Mid-Atlantic and snow will envelop much of the=20 Appalachians and Piedmont of the Southeast early Saturday morning.=20

On Saturday, the 500mb shortwave will take on a N-S neutral tilt=20
over the TN Valley and close off as it enters NW GA. PVA becomes=20
maximized over the Southeast while a surface low spawns along a=20
coastal front east of the Carolinas (with an additional surface low
moving out of the Bahamas). As the 850mb low deepens over northern
GA and heads east into SC, easterly 850mb theta-e advection will=20
direct low-level moisture around the 850mb low and support a band=20
of moderate-to-heavy snow from northeastern GA to central SC.=20
Farther north, the same tongue of 850mb theta-e is funneling along=20
the 850mb front to the north of the 850mb low track from northern=20
SC on east through much of NC. This is where the deformation zone=20
is likely to form, pivoting over central to eastern NC and northern
SC with 1-2"/hr snowfall rates likely. This band of heavy snow is=20
likely to reach farther east toward the Outer Banks (HREF=20
probabilities of >1"/hr at 00Z Sun, the end of the run, are >30%)=20
where 700mb FGEN is more ideally placed to support strong vertical=20 velocities within a fully saturated DGZ. These bands of heavy snow=20
in eastern NC and southeast VA depict 700-500mb lapse rates=20

6.5C/km Saturday afternoon and evening. It is here where not only=20

2"/hr snowfall rates are achievable, but so is the likelihood for=20 thundersnow. Note that the intense vertical velocities in eastern=20
NC and extreme southeast VA may result in some subsidence in north-
central NC and south-central VA. Snowfall is still likely to reach
warning criteria, but these regions are potentially susceptible to
lesser snowfall amounts as they are caught between the influence=20
of the strong upper-low to the south, and the strengthening coastal
low.

Speaking of the coastal low, along the VA/NC/SC coasts, not only=20
will the deformation zone of heavy snow pivot through, but the=20
explosive deepening of the storm east of Cape Hatteras will support
strong to potentially damaging wind gusts. ECMWF shows low=20
pressure south of Hatteras around 1008mb 12Z Saturday dropping to=20
around 970mb by 12Z Sunday east of Hatteras, indicative of rapid=20 intensification. With strong high pressure to the west, a strong=20
isallobaric flow will develop in response, creating wind gusts=20
along the DelMarVa coast on south through the Outer Banks that=20
could approach hurricane-force at times. These coastal areas=20
overlap with the ECMWF EFI in >0.8 values for both snow and wind,=20
making these areas most susceptible to blizzard conditions. Not to=20
be ignored either, strong wind gusts atop the Smokeys and Blue=20
Ridge are likely to top 60 mph as well, resulting in possible=20
blizzard conditions in those higher elevations of the southern=20
Appalachians. Power outages are likely in some parts of the=20
southern Mid-Atlantic, particularly areas at risk for those=20
hurricane-force wind gusts along the VA/NC coast.

Latest trends nudged the QPF footprint a bit southward but still=20
focused on NC into SC and grazing southeastern VA. By Sunday, the=20
trend of the system as it makes its closest pass to New England is=20
to be a bit farther southeast (away from the coast), and have=20
trended down the snow there in response. Locations that remain=20
susceptible are Cape Cod, Martha's Vineyard, and especially=20
Nantucket where WPC probabilities for at least 4 inches of snow are
around 50%.


Snowfall & Impacts...

For the event, WPC probabilities for at least 8 inches of snow are

50% from the Blue Ridge/Smokeys eastward across most of NC and=20

half of SC and along the VA/NC border. Eastern NC has the highest=20
chances (30-50%) of at least a foot of snow, depending on and band=20 placement. For context, some locations may see snowfall amounts not
seen since the 1970s/1980s (e.g., Feb. 1973, March 1980, or Dec.=20
1989) and could be a top ten event snowfall.=20

The snowfall could also be highly disruptive, not just during the=20
event, but for days after it is long gone. WSSI shows an expansive=20
area of Major Impacts (considerable disruptions to daily life;=20
dangerous to impossible travel, widespread closures, disruptions to infrastructure) from central SC (including Columbia, SC) through=20
the eastern two-thirds of NC (Charlotte/Raleigh-Durham). Along the=20
coast, WSSI shows Major to locally Extreme conditions from the=20
VA/NC border southward into the OBX and along the north and east-=20
facing shores of the Pamlico and Albemarle sounds, largely due the=20
blizzard potential and heavy snow. This speaks to the severity of=20
this major winter storm in the Carolinas. Lastly, with frigid=20
temperatures in the storm's wake on Sunday and lasting into=20
Tuesday, the snow will not melt much following the conclusion of=20
the storm. Any melting that occurs thanks to daytime heating is=20
likely to cause refreezing on untreated roads and surfaces.=20
Residents in the Carolinas should finish preparations as soon as=20
possible, as road conditions will be treacherous Saturday and into=20
the first half of next week.

Elsewhere, travel disruptions are possible as far south and west=20
as the Atlanta metro area where the WSSI shows Minor impacts with a
chance for an inch or so of snow on Saturday. Measurable snow may=20
cause hazardous travel as far west as the TN Valley and as far=20
south as Savannah where snowfall accumulations up to 1" are=20
possible. Moderate impacts (hazardous travel and some=20
infrastructure impacts) are also forecast in Charleston (SC), the=20 Smokeys/Blue Ridge of western NC/TN, and as far north as the=20
southern Richmond, VA suburbs. Impacts are still unclear in=20
southeast MA, but any snowfall will likely be accompanied by gusty=20
winds, causing blowing snow and reduced visibilities.=20


...Great Lakes...
Day 1...

Cyclonic flow will continue to favor lake effect snow across the=20
Great Lakes for another 36 hours or so. Frigid 850mb temperatures=20
will persist (around -18 to -24C, which are below the 10th=20
climatological percentile) over the rapidly freezing lakes. The N-S
band over Lake Michigan this morning will likely graze the WI/IL=20
shore before aiming into NW Indiana this evening/overnight as the=20
elongated vorticity lobe swings through. WPC probabilities for at=20
least 4 inches of snow are highest (40-60%) around Gary, IN.=20
Leftover lake snow on northerly flow will relax on Saturday as high
pressure briefly builds in from the west.=20


...Northern Great Plains, Upper Midwest, and western Great Lakes...
Days 1-3...

Tonight, a Pacific shortwave trough escorts Pacific moisture=20
eastward into the Northern Plains by Saturday morning, then into=20
the Upper Midwest Saturday evening into Sunday. Patches of freezing
rain in the northern High Plains on late Friday into Saturday are=20
expected given the favorable overrunning from WAA at low-mid levels
and sub-freezing surface temps. Farther east, snow is the more=20
likely precip type from the Red River of the North southward to the
Missouri Valley, then east to the Mississippi River and MN=20
Arrowhead/U.P/WI. Snow totals are forecast to range between 1-3" in
these areas late Saturday through Sunday into early Monday. Some=20
hazardous travel is possible, especially where roads temperatures=20
are likely below freezing in the wake of the recent extreme cold.


Fracasso/Mullinax


...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!_3gsfWHd4Rifi_CbV855Uh95BwMUxebkCOtdGLmsOVMQr= 5vQiqjacEqqVbSCNFdjb1Vfzm2V8IUKW9U7ZZxrzndtSh8$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!_3gsfWHd4Rifi_CbV855Uh95BwMUxebkCOtdGLmsOVMQr= 5vQiqjacEqqVbSCNFdjb1Vfzm2V8IUKW9U7ZZxr0nsBM1M$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 301835
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
135 PM EST Fri Jan 30 2026

Valid 00Z Sat Jan 31 2026 - 00Z Tue Feb 03 2026


...Southern Appalachians, Mid-Atlantic, & Southern New England...=20
Days 1-2...

...A major winter storm is expected to produce heavy snowfall and=20
blizzard conditions across the southern Mid-Atlantic...

The synoptic evolution continues to support a major winter storm,
primarily focused over the Carolinas, but questions about the
details continue.

The event begins this evening, as snow breaks out across the
southern Appalachians of NC/TN. This initial development of snow
will be in response to increasing synoptic ascent within strong
mid-level divergence downstream of a pivoting shortwave digging out
of the Great Lakes. As this shortwave dives southward out of the
Great Lakes, it will rapidly deepen into an impressive closed low
by 12Z Saturday over the Tennessee Valley, and then continue to
dive southeast, reaching the GA/SC coast by 00Z Sunday. This will
produce extreme anomalies of more than -5 sigma with respect to
500mb heights according to NAEFS across the Southeast/Gulf Coast,
indicative of how rare and extreme this setup will be. As the upper
low deepens and drops southward, forcing will intensify in response
to not only the mid-level divergence noted above, but additional
robust height falls, and increasing jet-level diffluence as a
downstream subtropical jet streaks strengthens across the Gulf and
then begins to arc poleward along the Southeast coast. This will
help generate surface cyclogenesis along the coast of the
Carolinas, with dual low-pressure systems progged, each one
deepening along the intense baroclinic gradient positioned offshore
owing to the recent extremely cold air blanketed across the eastern
CONUS.

The secondary surface low, which is likely to be the more intense
feature as it explosively intensifies Saturday night into Sunday
(maybe reaching into the 960s offshore) is progged to pivot more
east than northeast along the coast, so the heavy precipitation
should be generally confined to the Carolinas, southern VA, and
maybe Cape Cod as it pulls away. While there is continued
uncertainty into the exact amounts of precipitation due to dry air
aloft and intense mesoscale ascent that will drive bands of heavy
snow, there is high confidence in this overall synoptic evolution,
resulting in high confidence in the most impacted areas.

The column will be extremely cold, so other than possibly some
light rain along the coast to start the event, this will be an
all-snow scenario with above-climo SLRs, a rarity for this part of
the country. As noted above, the snow begins across the
Appalachians Friday evening and then expand rapidly to the south
and east as the upper low dives towards the Gulf and low pressure
development occurs offshore. This expansion of precipitation will
be driven primarily by increasing 850mb easterly flow, tapping into
the growing theta-e ridge offshore, with the resultant WAA leading
to the expanding snow shield, Some of this WAA could be intense as
reflected by strengthening 925-700mb fgen, well aligned into the
deep DGZ (>70% chance of at least 100mb of DGZ depth according to
the SREF). This will support not only expanding snowfall, but
intensifying snowfall such that by 00Z/Sunday at least moderate
snowfall rates should encompass nearly the entirety of the
Carolinas and into northeast GA and southern VA.=20

After 00Z Sunday is when the heaviest snow and most notable impacts
are expected as the low offshore deepens rapidly. This will pivot
winds to more N/NE across the region, and as a deformation axis
pivots west of the surface low and the cold conveyor sets up across
the Atlantic and into the eastern Carolinas, more intense ascent=20
and greater moisture should result in extreme (for this region)=20
snow rates. Cross-sections indicate a broad region of favorable=20
conditions for CSI, or even CI (thundersnow), and the HREF snow-=20
rate probabilities peak above 50% for 1"/hr suggesting at least a=20
potential for 2"/hr within a pivoting band somewhere in eastern NC=20
or SC, and this is additionally supported by the WPC prototype
snowband tool. These heavy snow rates will be accompanied by=20
strong winds that may gust 35-50 mph, higher at the coast and in=20
the mountains, suggesting near blizzard conditions in many areas.=20
While uncertainty remains into how dry air in the mid- level may=20
impact snow amounts on the broad scale, locally very significant=20
snowfall accumulations are likely, especially within these bands,=20
during D2. By Sunday afternoon the low will pull away bringing an=20
end to the snowfall and leaving just cold windy conditions in its=20
wake.

The exception will be across far southeast Massachusetts and onto=20
Cape Cod and the Islands where, despite a subtle southeast trend in
today's model guidance, periods of moderate snow are still expected
due to onshore flow and sufficient synoptic ascent into the
moistening column. A period of moderate snowfall is likely, with
some local enhancement south of Boston and on the Outer Cape due to
ocean influences, Sunday aftn/eve.

WPC probabilities for the event are quite robust for both the
Appalachians and eastern North Carolina, where they are above 50%
for 8+ inches, and 30-50% for 12+ inches. The greatest potential=20
for more than 12 inches appears to be eastern NC where the=20
deformation band may pivot, but a widespread 4-8" snowfall appears=20
likely from southern VA through northern SC, with impactful=20
accumulations expected in areas like Richmond, VA, Charlotte and=20
Raleigh, NC, Columbia, SC, and even into Atlanta, GA. Farther=20
northeast, WPC probabilities are 30-50% for 4+ inches across the=20
Cape and Islands.

Key Messages are in effect for this storm, and are linked below
(Key Message #2).=20


...Great Lakes...
Day 1...

Potent shortwave diving southward within broad cyclonic flow into=20
the Tennessee Valley Saturday morning will rapidly sharpen the
eastern CONUS trough leaving pronounced CAA on northerly flow in
its wake. This will result in continued lake effect snow (LES),
especially in the favored north snow belts south of Lake Ontario
and especially south of Lake Michigan where the long fetch of the
lake will be maximized to produce a narrow band of heavy snowfall.
Although the lakes are cooling and have much higher ice coverage
than a week or two ago, frigid 850mb temperatures moving overhead
will create strong delta-Ts to support snowfall rates that have a
30-40% chance (from the HREF) of exceeding 1"/hr, greatest across
NW Indiana. While some light accumulations are likely south of Lake
Ontario, WPC probabilities for 4+ inches are confined to NW IN
where they reach 30-50%.


...Northern Plains through the Upper Midwest and Great Lakes...=20
Days 1-3...

A shortwave emerging from the Pacific will crest the ridge over the
Pacific Northwest and then dive slowly southeast into the Northern
Plains and then amplify into a deeper trough as it moves into the
Great Lakes and then elongate towards the Tennessee Valley. This
feature will generally be of modest amplitude and remain
progressive, so large scale forcing for ascent will be modest and
driven by mid-level divergence downstream of the trough overlapping
modest warm advection/isentropic ascent. The result of this will be
axes of both light freezing rain and snow in many areas from
eastern MT through the western Great Lakes. WPC probabilities for
2"+ of snowfall are as high as 30-50% D2 across central/northern
MN, and similar for parts of the U.P. and western L.P. of MI D3.
For freezing rain, WPC probabilities are as high as 30% for 0.1"=20
in western ND on D1, but are generally less than 10% elsewhere=20
through the period. However, light freezing rain accreting above=20
0.01" is possible for much of Montana and the Dakotas.

Weiss



...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!_zv2HEUaCxHmrxcjxPpQ_d45hb_EFdwDQXzo01Egj7qkP= UXe0KoqO0O81tc8GJAqH6nRw9ZPdRN7lhhSqjXZph7rlAQ$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!_zv2HEUaCxHmrxcjxPpQ_d45hb_EFdwDQXzo01Egj7qkP= UXe0KoqO0O81tc8GJAqH6nRw9ZPdRN7lhhSqjXZerjYTzs$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 310710
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
210 AM EST Sat Jan 31 2026

Valid 12Z Sat Jan 31 2026 - 12Z Tue Feb 03 2026


...Southern Appalachians, Mid-Atlantic, & Southern New England...=20
Days 1-2...

...A major winter storm is expected to produce heavy snowfall and=20
blizzard conditions across the southern Mid-Atlantic...

Sharp mid-level trough over the mid-MS Valley early this morning=20
will close off into a potent upper low over Middle TN by 12Z. The=20
pattern over the East Coast will feature an increasingly amplified=20
pattern (e.g., strengthening S-shaped upper jet) that will support=20
explosive cyclogenesis off the Carolina coast this=20
evening/overnight. With an arctic air mass already in place, nearly
all of the precipitation will be snow even at onset. The system=20
will quickly lift up the coast (outside the 40/70 benchmark) and=20
clip southeastern New England as it races into Atlantic Canada=20
tomorrow.=20

First part of the system is underway over the southern=20
Appalachians with light to modest snow over the Smokeys into SW VA=20
beneath lower-level FGEN and incoming height falls/PVA. Snow will=20
expand southward today over WNC and Upstate SC as well as northeast
GA as the upper low tracks over ATL to CHS by this evening. To its
north, near the path of the developing 850mb low, the snow could=20
fall heavy at times today with 1"/hr rates possible (10-40% chance=20
per the CAM guidance) into the Charlotte metro. As the upper low=20
reaches the coast around 06Z Sun, banded snow could sink=20
southeastward into northeastern SC (Myrtle Beach/The Grand Strand).
By this time, the coastal low will have begun its rapid=20
intensification, which leads into the other part of the system.=20

With the coastal low intensifying through the 990s to 970s mb, N=20
to NE flow at the surface over eastern and northeastern NC into=20
extreme southeastern VA will increase as snow continues to fall.=20
The increasing 850mb northeasterly/easterly flow, tapping into the=20
growing theta-e ridge offshore, coupled with WAA and strengthening=20
925-700mb FGEN, will support >1"/hr rates over eastern NC after 00Z
Sun. Deformation axis should pivot west of the surface low and the
cold conveyor sets up across the Atlantic and into the eastern=20
Carolinas to support those rates. Cross-sections indicate a broad=20
region of favorable conditions for CSI, or even CI (thundersnow),=20
which is not unusual in highly dynamic and rapidly intensifying=20
systems. The column is quite cold, and SLRs should be well above=20
climo with a deep DGZ (>13:1 to near 20:1). These heavy snow rates=20
will be accompanied by strong winds that may gust 35-50 mph, higher
at the coast, suggesting near-blizzard conditions in many areas.

One question in the forecast, per the 00Z guidance, is what=20
happens in between these two main drivers of heavier snow areas;=20
i.e., in the I-85/95 corridors in NC. Some CAM guidance shows an=20
extreme min (near zero snow) while other guidance shows at least=20
several inches. CAM guidance could be overdoing the mesoscale=20
response of oscillatory subsidence/lift surrounding the system, but
it certainly is unusual to see this much spread just before the=20
start of the event. Trimmed down the amounts here from the previous
forecast but not to the extent of the 00Z CAMs.=20

By Sunday afternoon the low will pull away bringing an end to the=20
snowfall and leaving just cold windy conditions in its wake. To the
northeast, despite a track just outside the 40/70 benchmark, the=20
expansive system will likely clip far southeast Massachusetts=20
(southeast of I-95) and Cape Cod and the Islands where periods of=20
moderate snow are expected due to onshore flow and sufficient=20
synoptic ascent into the moistening column. A period of moderate=20
snowfall is likely, with some local enhancement south of Boston and
on the Outer Cape due to ocean influences, Sunday aftn/eve.

WPC probabilities for at least 6 inches of snow are >50% over much
of western NC, across the border to upstate SC, southeastward to=20
the coast, and the northeastward up the coast into extreme=20
southeastern VA. Lower probabilities around 30% exist along the VA=20
border and over southwestern SC. Mesoscale bands will likely=20
enhance snowfall over some areas resulting in >10-12" snow. A=20
broader area of light snow is expected surrounding the system, with
WPC probabilities for at least 1" of snow >50% as far west as=20
Atlanta, south to near Savannah, and on the north side up to=20
Richmond, VA and Salisbury, MD on the DelMarVa. In MA, WPC=20
probabilities for at least 4 inches of snow are >30% over the Cape=20
and Martha's Vineyard but >50% over Nantucket.=20


Key Messages are in effect for this storm, and are linked below=20
(Key Message #2).=20


...Northern Plains through the Upper Midwest and Great Lakes...=20
Days 1-3...

And advancing warm front over the western High Plains this morning
will continue eastward, bringing the chance for some snow and=20
freezing rain as milder Pacific air overruns the cold surface. The=20
system will continue eastward Sunday into the western Great Lakes=20
and through MI to the eastern Great Lakes Monday. Amounts will be=20
light, generally 1-3", as the system remains progressive. WPC=20
probabilities for at least 4" are around 10% over portions of the=20
Red River Valley (ND/MN border) and perhaps the Keweenaw Peninsula=20
wit some lake enhancement after the front moves to the east.=20


Fracasso/Weiss


...Winter Storm Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!4XEwcjZbPCsaopLdDZHr3UrVyP5HfOPX16r-Ffei8ZPsV= DY7_6OXc-aU-DKV2da-bl6n6tCr8zwqm953Cu8HX5EO-2M$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!4XEwcjZbPCsaopLdDZHr3UrVyP5HfOPX16r-Ffei8ZPsV= DY7_6OXc-aU-DKV2da-bl6n6tCr8zwqm953Cu8H32009l4$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 311936
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
236 PM EST Sat Jan 31 2026

Valid 00Z Sun Feb 01 2026 - 00Z Wed Feb 04 2026


...Southern Appalachians, Mid-Atlantic, & Southern New England...=20
Day 1...

...A major winter storm will produce heavy snowfall across the
southern Mid-Atlantiuc and blizzard conditions along the North
Carolina coast through tonight and into Sunday morning...

The major winter storm is unfolding with periods of snow, falling=20
heavily at times, from the southern Appalachians and eastern GA on=20
east through the Carolinas and into far southern VA. This morning,=20
the 850mb low has formed and is tracking towards southern SC with a
tongue of rich 850mb theta-e air rotating around the northern and=20
western flanks of the low. As the low strengthens, so does the=20
easterly fetch supplying Atlantic moisture, resulting in a=20
broadening shield of snow from as far west as the Atlanta metro to=20
even as far south as Savannah, GA today. As strong 500mb PVA moves
in aloft, a band of heavy snow is likely to unfold over eastern GA
that could then pivot over southern SC, including the Charleston=20
metro area. The heaviest snow rates are likely to occur north of=20
the 850mb low track where easterly low-level winds are enhanced via
upslope flow from the hills near Charlotte on west into the=20
southern Appalachians. Snowfall rates of 1-2" per hour are likely=20
there, resulting in dangerous to even impossible travel conditions.
WPC probabilities show moderate chances (40-60%) for additional=20
snowfall totals >4" from Charlotte on south into central SC and=20
eastward to northeast SC and the Cape Fear Tidewater region.=20

Central NC and southern VA are caught between the impressive=20
dynamics closer to the highly anomalous upper-low to the south and
west, and the developing coastal low that will rapidly strengthen=20
east ot the Outer Banks today and into tonight. Guidance has come into
better agreement on a depression in the expected QPF footprint=20
around the Raleigh-Durham area on north and east along I-85 into=20 south-central VA. While totals have trended down, it is=20
exceptionally cold with highs unlikely to get above the mid 20s=20
today. Plus, occasionally gusty winds this afternoon and evening=20
will cause reduced visibilities and blowing snow on roads. WPC=20
probabilities still show moderate-to-high chances (50-80%) for=20
snowfall totals >2" in these areas, with better odds for >4" on=20
southward along I- 95 and I-40. Snow will have no trouble sticking=20
and travel will be hazardous through this evening and into tonight.
Expect slick roads to persist into Sunday as temperatures will=20
struggle to get above freezing, and any melting that does occur on=20
Sunday on roadways has a high chance to refreeze Sunday night and=20
Monday morning.

Farther east into eastern NC and southeast VA, the storm system
along the coast will rapidly strengthen by as much as 40mb in 24
hours. Not only will a band of 1-2"/hr snowfall rates ensue this
afternoon and into tonight, but wind will ramp up in intensity
significantly, especially along the Outer Banks and on north/east
facings shores of the Pamlico and Albemarle Sounds. Steepening
lapse rates as the mid-upper level low approaches the warmer shelf
waters will also support some instability in the 850-500mb layer,=20
allowing for thundersnow to be a potential phenomenon for those in=20
eastern NC. Snow will continue over the eastern tidal areas of NC=20
and southeast VA through early Sunday morning, but snow should=20
taper off by midday Sunday as the powerful winter storm races east=20
into the west Atlantic. WPC probabilities show moderate- to-high=20
chances (50-80%) for snowfall totals >6" from the Myrtle Beach area
and the Cape Fear region on north through much of eastern NC.=20
Given the robust 1-2"/hr rates in eastern NC, there is a low-to-
moderate chances (30-50%) for localized snowfall totals to surpass=20
12" by the time this event concludes late Sunday morning. As=20
mentioned above, the bitter cold in wake of the storm will keep=20
travel on all roadways across eastern and southern NC treacherous=20
into the start of the work/school week.=20

Lastly, trends have been to gradually decrease snowfall totals in
southeast MA, although some measurable snow and blowing snow is
likely over Martha's Vineyard, Nantucket, and the MA Capes. WPC
probabilities show low-to-moderate chances (30-60%) for snowfall
totals >4" here, with Nantucket sporting the highest chances for

6" given their closer proximity to the winter storm on Sunday.

Key Messages are in effect for this storm, and are linked below=20
(Key Message #2).=20


...Northern Plains through the Upper Midwest and Great Lakes...=20
Days 1-3...

An advancing warm front associated with low pressure over southern
Canada is tracking across the North Central U.S. today will=20
continue eastward, producing light snow and minor freezing rain in=20
the Northern Plains as milder Pacific air overruns the cold=20
surface. The warm front marches eastward Sunday into the Upper
Midwest and Great Lakes, then into Michigan and the eastern Great=20
Lakes Monday. Amounts will be light, generally 1-3", as the system=20
remains progressive. Another round of light snow arrives in the
northern High Plains on Monday and ending Monday night, but totals
are likely to be below 3 inches.


...Ohio Valley & Central Appalachians...
Day 3...=20

The shortwave trough responsible for light snow in the northern
High Plains on Monday dives south into the Middle MS Valley early
Tuesday morning and races into the OH Valley by Tuesday afternoon.
Weak 850-700mb WAA and a tongue of 700-300mb moisture aloft will be
available aloft and will allow for snowfall. Most snowfall amounts will
be generally a coating-2", although the central Appalachians in=20
eastern WV have low-to-moderate chances (30-50%) for snowfall=20
amounts >2". This weak feature has a chance to produce light snow=20
in portions of the Mid-Atlantic on Wednesday.


Mullinax



...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!_FsdXoLtiJKgZ9SEV8EVy4DoOUHafubqMkLCzThr-B36g= 9DWF1LlOJ9JGlBYJP21r3EHc_EHIKUVPBZmdQbPfoMGK1g$=20

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!_FsdXoLtiJKgZ9SEV8EVy4DoOUHafubqMkLCzThr-B36g= 9DWF1LlOJ9JGlBYJP21r3EHc_EHIKUVPBZmdQbPrJyhzgw$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 010630
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
130 AM EST Sun Feb 1 2026

Valid 12Z Sun Feb 01 2026 - 12Z Wed Feb 04 2026


...Southeastern Massachusetts...
Day 1...

The powerful winter storm exiting the Carolinas this morning will=20
graze southeastern New England today with generally light snow but=20
very gusty winds. WPC probabilities for at least 4 inches of snow=20
are 10-30% over Nantucket and into parts of Cape Cod (e.g.,=20
Chatham).=20


...Northern Plains through the Upper Midwest and Great Lakes...=20
Days 1-3...

A surface front will move out of the Upper Midwest into the=20
western Great Lakes today then into Michigan and the eastern Great=20
Lakes Monday. Snow will be light, generally 1-3", as the system=20
remains progressive. Another round of light snow arrives in the=20
northern High Plains on Monday and ending Monday night, but totals=20
are likely to be below 3 inches. Some areas in the U.P. may see=20
several inches of the three-day period with modest lake effect snow
behind the front.=20


...Ohio Valley & Central Appalachians...
Day 3...=20

The shortwave trough responsible for light snow in the northern=20
High Plains on Monday will dive into the Middle MS Valley early=20
Tuesday morning and race into the OH Valley by Tuesday afternoon=20
and the Mid-Atlantic by Wednesday morning. Weak 850-700mb WAA and=20
mid-level moisture will favor light snowfall in a west-to-east=20
areas. Most snowfall amounts will be generally a coating-2", but=20
some upslope enhancement into the central Appalachians may allow=20
for a bit more. Here, WPC probabilities for at least 4 inches of=20
snow are low (10-20%). Light snow will extend eastward into the=20
Mid-Atlantic early Wednesday.


Fracasso


...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!9GBpM9epRWaJGrcPUfEKW7ns0MQShIt24-3aSTYra4iBS= yEc4zdUJy3kS0uC9meUdSdqsB6te8uKUm4NjS4o-T7c-Og$=20


$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 011800
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
100 PM EST Sun Feb 1 2026

Valid 00Z Mon Feb 02 2026 - 00Z Thu Feb 05 2026

...Northern Plains through the Great Lakes...=20
Days 1-2...

A shortwave on the upstream side of an amplified trough (500mb
heights below the 1st percentile according to NAEFS) will dig
southeast from Saskatchewan while a secondary shortwave deepens
into a closed low over Ontario. Together, these features will drive
a surface cold front eastward from the Northern Plains to the Great
Lakes D1 before continuing into the Ohio Valley D2. The overlapping
ascent between height falls/PVA and low-level convergence, along
with modest frontogenesis and subtle WAA will result in an axis of
light to at times moderate snow, with the heaviest likely occurring
in response to lake enhancement east of Lake Michigan and across
the U.P. in the NW snow belts. WPC probabilities are modest overall
as available moisture is limited, but locally as much as 4" of snow
is possible (10-30%) across the U.P. and far NW L.P., with less
than 2" expected elsewhere. Additionally, some light freezing rain
is also possible driven by dryness within the DGZ, and WPC
probabilities for 0.01+" of ice are 10-30% across portions of the
Dakotas D1.


...Ohio Valley, Central Appalachians, and Mid-Atlantic...=20
Days 2-3...

A fast moving shortwave diving out of Alberta will drop southeast
around the western CONUS high and into the Mid-Mississippi Valley
Tuesday morning. This shortwave will amplify, at least subtly, as
it translates to the southeast, maintaining a positive tilt but
interacting with a cold front digging across the Ohio Valley. At
the same time, a subtropical jet streak draped along the Gulf Coast
will gradually intensity in response to the trough amplification,
and begin to pivot poleward, with the response to this evolution
being a surge in moisture lifting out of the Gulf noted by a strung
out theta-e ridge from the FL Panhandle into the Mid-Atlantic. This
moisture return will be aided by at least modest WAA, and the
guidance has trended upward just a bit in its QPF potential, and
has shifted northward somewhat as well.

The WAA lifting isentropically atop the cold front into the colder
airmass should result in a swath of light to moderate snowfall,
although locally heavier rates are possible due focused fgen into
the deepening DGZ, and this is reflected by significant spread in
the latest WSE plumes, despite a focus of mostly light snowfall
amounts. Current WPC probabilities are low (10-30%) D2 for at least
2 inches across the Central Appalachians of WV (where upslope
enhancement is likely), and moderate (30-50%) in that same area D3
suggesting localized totals of 4" are possible. Elsewhere, WPC
probabilities suggest moderate risk (30-70%) for more than 1 inch=20
across the lower Ohio Valley and a 10-30% for similar accumulations into
the Mid- Atlantic states including Washington, D.C.

Some light freezing rain is also possible with this wave as it
swings eastward, mostly due to loss of cloud ice vs warm nose
development, which could result in a swath of ice accretion above
0.01" (10-30% chance) from western KY/TN into VA/NC. Any ice is
hazardous, but this could be more problematic than usual due to
continued recovery efforts from the recent winter storms.


...Pacific Northwest...
Day 1...

A modest Pacific jet streak will lift northeast atop a west coast
ridge Monday, bringing with it a brief period of IVT exceeding the
90th climatological percentile according to NAEFS. A warm front
will push onshore and lift northeast concurrently with this jet
streak, leading to a brief period of enhanced WAA/precipitation
before snow levels climb rapidly into D2. This will result in a
period of rain and snow across the Washington Cascades, and
although snow level forecasts are generally above pass level, a few
inches of snow is possible between 3000-4000 ft before turning to=20
rain. WPC probabilities for 4+ inches of snow are above 70% only in
the higher Washington Cascades, but a few slushy inches of=20
accumulation is forecast at Stevens Pass leading to hazardous
travel Monday afternoon.

Weiss


...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!9YRGIGSlDRwz1Kt4s7H_JQxQxrQrLi-hlxXkhTcc2PeqV= OUwi_taivHgsFXvEnCrMLHMjTJRc9mduyxC6l5q8VK4ssU$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 020713
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
213 AM EST Mon Feb 2 2026

Valid 12Z Mon Feb 02 2026 - 12Z Thu Feb 05 2026


...Pacific Northwest...
Day 1...

A weak shortwave and surface warm front will move through the
region this morning with some light snow for areas mainly above
4000ft, with snow levels rising sharply later today. WPC
probabilities for at least 4 inches of snow are >50% above 4000ft
or so.

...Great Lakes...
Day 1-1.5...

Weak system will spread slight snow across the Great Lakes (1-2")
today into Tuesday with some lake effect snow behind it, mostly
over the U.P. of Michigan. There, WPC probabilities for at least 4
inches of snow are 20-40%.

...Northern Plains...
Day 1...

A shortwave in southern Canada will dive southeastward through
North Dakota this morning, with generally light to locally modest
snow along a thermal gradient. Some banded snow could develop and
support a few inches of snow, and WPC probabilities for at least 4
inches are 30-70% over north central North Dakota.

...Ohio Valley, Central Appalachians, and Mid-Atlantic...
Days 2-3...

The shortwave over the northern Plains Day 1 (above) will dive
into the Mid-MS Valley tomorrow morning and through the Ohio Valley
tomorrow evening. At the same time, Gulf moisture will lit
northeastward through the Lower MS Valley to yield some light snow
on the northern side of the precip shield. WAA-driven snow is
likely along the Ohio River Tuesday morning eastward to the central Appalachians tomorrow evening and into early Wednesday, also
spreading to the Mid-Atlantic. Amounts will generally be light, but
some upslope enhancement in eastern WV could yield a few inches of
snow. WPC probabilities for at least 4 inches of snow are around
30-40% above 3000ft. 1-3" of snow is possible (>50% chance) from
around Cincinnati eastward. Lower chances of just 1" are seen along
the I-95 corridor from DC to PHL, but this could coincide with the
Tuesday evening rush hour or possibly Wednesday morning depending
on the speed of the system.

Some light freezing rain or drizzle is also possible with this
wave over KY/TN into VA/NC. Any ice is hazardous, but this could be
more problematic than usual due to the recent winter storm(s).


Fracasso


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 021935
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
235 PM EST Mon Feb 2 2026

Valid 00Z Tue Feb 03 2026 - 00Z Fri Feb 06 2026


...Great Lakes...
Days 1-2...

A weak system will continue to spread light snow showers across
the Great Lakes tonight into Tuesday with some lake effect snow
following in its wake. Snowfall accumulations of 1-2" are likely
across portions of MI and western NY, with localized 20-40%
probabilities of >4" in the U.P of MI and localized 40-60%
probabilities downwind of Lake Ontario.


...Ohio Valley, Central Appalachians, and Mid-Atlantic...
Days 1-3...

A shortwave over the northern Plains will dive into the Mid-MS
Valley by Tuesday morning before reaching the Ohio Valley by
Tuesday evening. Ahead of this wave, weak surface low pressure will
develop over the Lower MS Valley, helping to draw Gulf moisture
northward. The increasing moisture and warm air advection combined
with large scale forcing for ascent within the left exit region of
a strengthening 250mb 100kt+ jet streak will yield a swath of
banded snow from southeast IN and southern OH Tuesday morning
eastward to the central Appalachians Tuesday evening into Wednesday
morning. WPC probabilities for snowfall >2" are 30-60% across a
fairly narrow corridor from southeast IN eastward along and just
north of the Ohio River and into WV. Banded snowfall could also
lead to localized higher amounts, with low but not zero
probabilities of >4" around 5-10%. Upslope enhancement may also
push accumulations above 4" in the higher elevations of WV, with
probabilities of 20-40% mainly above 3000ft.

Some light snow or flurries could survive the trip over the
central Appalachians into parts of the Mid-Atlantic late Tuesday
night into Wednesday morning, but trends for even just 1" of snow
have been decreasing with probabilities now only 10-20% across
portions of northern VA, northern MD, DE, and southern NJ. Still,
any snow combined with the recent cold and timing of early morning
rush hour could be enough to cause localized travel concerns. What
could be more interesting and worth monitoring is how much more the
wave develops as it begins to exit the Mid-Atlantic coast
Wednesday afternoon and evening. Latest trends have been a bit more
wintry across parts of southern VA and northern NC, and while poor
thermals are likely limiting probabilities of accumulating
snowfall at the moment, a deeper wave and greater dynamic cooling
could change that in the coming days.

In between the transition from snow to rain, some light freezing
rain or drizzle is also possible with this wave over KY/TN into
VA/NC. Any ice is hazardous, but this could be more problematic
than usual due to the recent winter storm(s).


Miller


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 030804
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
304 AM EST Tue Feb 3 2026

Valid 12Z Tue Feb 03 2026 - 12Z Fri Feb 06 2026


...Great Lakes...
Day 1...

A weak system moving through the Great Lakes this morning will spread
light snow showers over the region with some lake effect snow
following in its wake. Snowfall accumulations of 1-3" are likely
across portions of the U.P. of Michigan and near Watertown, NY. WPC probabilities of >4" are low (10-20%).

Day 3...

A 140kt jet over south central Canada Thursday will help push a
warm front through the western Great Lakes, followed by a strong
arctic cold front that will cross into the region by Friday
morning. This will bring a period of snow focused on Michigan which
will lie near/north of the stronger height falls along the fronts.
Through 12Z Friday, generally light snow but increasing winds over
the region will usher in much colder air. WPC probabilities for at
least 4 inches of snow through 12Z Fri are low (10%) but blowing
snow could be the bigger hazard, especially near the lake shores.


...Ohio Valley, Central Appalachians, Mid-Atlantic, Carolinas...
Days 1-2...

A shortwave over the Corn Belt this morning will reach the Ohio
Valley this evening. Ahead of this wave, weak surface low pressure
will develop over the Lower MS Valley, helping to draw Gulf
moisture northward. The increasing moisture and warm air advection
combined with large-scale forcing for ascent within the left exit
region of a strengthening 250mb 100kt+ jet streak over the Mid-
South will yield a swath of banded snow from southeast IN and
southern OH eastward to the central Appalachians today into tonight.
Amounts will be light (Minor impacts per the WSSI) and WPC
probabilities for snowfall >2" are 30-60% across a fairly narrow
corridor from northern KY (CVG) eastward along and just north of
the Ohio River and into WV. Banded snowfall could also lead to
localized higher amounts, with low but non-zero probabilities of

4" around 5-10%. Upslope enhancement may also push accumulations

above 4" in the higher elevations of WV, with probabilities of
20-40% mainly above 3000ft.

Some light snow should crest the central Appalachians into parts
of the Mid-Atlantic late Tuesday night into Wednesday morning, but
this can sometimes dry up east of I-81. WPC probabilities for 1" of
snow are generally <15% along the I-66/Rt 50 corridor across
northern VA, DC, MD, and into DE. Still, any snow combined with
the recent cold could be enough to cause localized travel
concerns.

As the front continues southeastward, trailing shortwave energy may
slow the southern portion of the front over the Southeast, allowing
a weak area of low pressure to form over the southern Appalachians
on Wednesday. As the low moves slowly through GA/SC Wednesday
evening and off the coast early Thursday, moisture will linger over
southern VA and much of northern/western NC where temperatures are
marginally supportive of snow. During the overnight hours, dynamic
cooling could support some light accumulation of 1-2" over
southwestern VA and northern NC where WPC probabilities of >2" of
snow are 30-60%.

At the same time, enough northerly component of the wind could
drain some sub-freezing boundary layer air into eastern NC and
support light icing of around 0.01" or so. Any ice is hazardous,
but this could be more problematic than usual due to the recent
winter storm(s).


Fracasso/Miller



$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 031900
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
200 PM EST Tue Feb 3 2026

Valid 00Z Wed Feb 04 2026 - 00Z Sat Feb 07 2026


...Ohio Valley, Central Appalachians, Mid-Atlantic, Carolinas...=20
Days 1-2...

Increasing moisture and warm air advection ahead of a weak surface
low over the Mid South combined with large-scale forcing for=20
ascent within the left exit region of a strengthening 100kt+ upper=20
level jet streak will yield a swath of snow from eastern KY eastward
to the central Appalachians tonight into early Wednesday. Amounts=20
will be light (Minor impacts per the WSSI) and WPC probabilities=20
for snowfall >2" are 30-60% mainly across the higher elevations of=20
WV and southwest VA.

Some light snow should also crest the central Appalachians into=20
parts of the Mid-Atlantic late tonight into Wednesday morning, but
this can sometimes dry up east of I-81. WPC probabilities for 1"=20
of snow are generally <15% along the I-66/Rt 50 corridor across=20
northern VA, DC, MD, and into DE. Still, any snow combined with the
recent cold could be enough to cause localized travel concerns,
particularly during the Wednesday morning commute.

As the front continues southeastward, trailing shortwave energy may
slow the southern portion of the front over the Southeast, allowing
another weak area of low pressure to form over the southern=20
Appalachians on Wednesday. As the low moves slowly through GA/SC=20
Wednesday evening and off the coast early Thursday, moisture will=20
linger over southern VA and much of northern/western NC where=20
temperatures are marginally supportive of snow. During the=20
overnight hours, dynamic cooling could support some light=20
accumulations around an inch or so across southern VA and northern
NC, especially across the higher elevations of southwestern VA and
northwest NC where WPC probabilities of >2" of snow are 20-40%.

In the wake of the departing low pressure system, lingering low-=20
level upslope moisture combined with mid-level drying may lead to a
period of freezing drizzle across parts of eastern KY, southwest=20
VA, eastern TN, and western NC late tonight into Wednesday morning.
Anywhere the freezing drizzle is more persistent could produce a=20
light glaze of ice. Additionally, enough northerly component of the
wind could drain some sub-freezing boundary layer air into far=20
southeastern VA and eastern NC, supporting light icing of around=20
0.05" or so later Wednesday night into early Thursday morning.=20
While any ice is hazardous, the icing noted above could be more=20
problematic than usual due to the recent winter storm(s).


...Great Lakes, Central Appalachians, Mid-Atlantic...=20
Day 3...

A 140kt upper level jet over south central Canada Thursday will=20
help push a warm front through the western Great Lakes, followed by
a strong Arctic cold front that will dive to the south and east across
the region through the day on Friday. The left exit region of this
jet combined with a potent vort max will increasingly support=20
large scale forcing for ascent, with weak surface low development=20
possible downstream of the western Great Lakes. This will support=20
widespread snow showers and the potential for snow squalls from
MI and western NY to OH, PA, and WV starting late Thursday night=20
and continuing through the day on Friday. Some of the stronger=20
showers and squalls are looking increasingly likely to spill over=20
the central Appalachians into parts of the Mid-Atlantic later in
the afternoon, possibly impacting the evening commute. WPC=20
probabilities for >2" of snow are 40-70% across parts of MI,=20
northeast OH, northwest PA, and the higher elevations of southwest=20
PA and WV. Probabilities for >4" of snow are 10-20% for portions of
the U.P. of MI, northeast OH, and WV.=20

In the wake of the Arctic front, a blast of bitterly cold air will
encompass much of the Northeast heading into the weekend. For more
details, please reference the Extreme Cold Key Messages in the link
provided below.


Miller/Fracasso


...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!5j_1Fl9dotMFlsl07RquALPtLY120Rf8RXpm3UvO9h2Aq= WTyEVokCe1dREqejgH5zKFQcTSSV5HeegGtRiqqlHSH2qw$=20


$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 040716
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
216 AM EST Wed Feb 4 2026

Valid 12Z Wed Feb 04 2026 - 12Z Sat Feb 07 2026


...Southern Mid-Atlantic...
Day 1...

A cold front over the Southeast this morning and area of low=20
pressure over the southern Appalachians will make a slow march=20
eastward today with rain over much of the region but some light=20
snow on the northern side of the precipitation shield. Trailing=20
shortwave energy from the Lower MS Valley/Mid-South will slow the=20
front a bit tonight as temperatures cool just enough over southern=20
VA into northern NC for snow to fall and accumulate. In addition,=20
lingering moisture over eastern NC tonight combined with mid-level=20
drying may lead to some freezing rain and freezing drizzle. Though=20 accumulations will be light (0.01-0.05"), any freezing rain is=20
impactful to untreated surfaces. Precipitation will end from west=20
to east Thursday.

WPC probabilities of at least 2 inches of snow are 20-50% over=20
southwestern VA and barely 10% over northern/northeastern NC.=20


...Great Lakes, Central Appalachians, Northeast, Mid-Atlantic...=20
Days 1-3...

A warm front will push into the Upper Midwest and western Great=20
Lakes, aided by a 140kt upper level jet over south central Canada=20
on Thursday. Light and broad WAA-driven snow is forecast for=20
northeastern MN and across the Upper and Lower Peninsulas of=20
Michigan. This will be followed by a strong Arctic cold front that=20
will dive to the south and east across the region through the day=20
on Friday. The left exit region of this jet combined with a potent=20
vort max will support large-scale forcing for ascent across the=20
Great Lakes in the wake of the lead light snow. With the passage of
the Arctic front, snow squalls are possible from MI and western NY
to OH, PA, and WV starting late Thursday night and continuing=20
through the day on Friday. Some of the stronger showers and squalls
are looking increasingly likely to spill over the central=20
Appalachians into parts of the Mid-Atlantic later in the afternoon,
possibly impacting the evening commute on Friday. Upslope snow in=20
the central Appalachians should maximize Friday afternoon/evening=20
as the front moves through.=20

WPC probabilities for at least 4 inches of snow are low (10-40%)=20
across the U.P. of Michigan and west of Traverse City. Over western
NY and NW PA, surface low may move through the region and spur=20
more widespread snow along/behind the front and as winds turn more=20 northerly, picking up moisture off Lake Ontario. There, WPC=20
probabilities for at least 4 inches of snow are 20-50%. Finally,=20
over eastern WV, amounts will likely be the highest in the region=20
and WPC probabilities for at least 4 inches of snow are >70%,=20
especially above 2000ft.=20

In the wake of the Arctic front, a blast of bitterly cold air will
encompass much of the Northeast heading into the weekend. For more
details, please reference the Extreme Cold Key Messages in the=20
link provided below.

Fracasso


...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!7tsD76lSRVfHX36EwdU0bUH9sv7W5vUQCPqiaIzI-ixFR= Gd4LUnOvsu70q0yzEm9RwTuYw8BtsBuDJVbB7gEJeEI6qI$=20


$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 041942
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
242 PM EST Wed Feb 4 2026

Valid 00Z Thu Feb 05 2026 - 00Z Sun Feb 08 2026


...Southern Mid-Atlantic...
Day 1...

An area of low pressure riding along a cold front that is tracking
across the Southeast will bring some wintry precipitation on the
northern fringe of the precipitation shield along the VA/NC border
tonight. Rain and a wintry mix will change over to snow, while for
portions of central and eastern North Carolina, mid-level drying
with a slow exit of the low level moisture will support a period of
freezing drizzle, which could accumulate to a few hundredths of an
inch on untreated surfaces tonight. Both precipitation and
associated impacts should end within a couple hours of sunrise
Thursday.=20

WPC probabilities of 0.01 inches of ice is around 80% for portions
of North Carolina between Greenville and Fayetteville, and up to
30% for 0.10 inches of ice. Snow probabilities for an inch of snow
are between 20-40% along the VA/NC border, and up to 50% along I-81
southwest of Roanoke, VA.=20



...Great Lakes, Central Appalachians, Northeast, Mid-Atlantic...=20
Days 1-3...

A warm front will push into the Upper Midwest and western Great=20
Lakes, aided by a 140kt upper level jet over south central Canada=20
on Thursday. Light and broad WAA-driven snow is forecast for=20
northeastern MN and across the Upper and Lower Peninsulas of=20
Michigan. This will be followed by a strong Arctic cold front that=20
will dive to the south and east across the region through the day=20
on Friday. The left exit region of this jet combined with a potent=20
vort max will support large-scale forcing for ascent across the=20
Great Lakes in the wake of the lead light snow. With the passage of
the Arctic front, snow squalls are possible from MI and western NY
to OH, PA, and WV starting late Thursday night and continuing=20
through the day on Friday. Some of the stronger showers and squalls
are looking increasingly likely to spill over the central=20
Appalachians into parts of the Mid-Atlantic later in the afternoon,
possibly impacting the evening commute on Friday. Upslope snow in=20
the central Appalachians should maximize Friday afternoon/evening=20
as the front moves through.=20

WPC probabilities for at least 4 inches of snow are low (10-30%)=20
across the U.P. of Michigan and west of Traverse City. Over western
NY and NW PA, surface low may move through the region and spur=20
more widespread snow along/behind the front and as winds turn more=20 northerly, picking up moisture off Lake Ontario. There, WPC=20
probabilities for at least 4 inches of snow are 20-40%. While there
is a considerable amount of ice cover on the Great Lakes, just
under 50% according to the USNIC, there remains enough open water
on all but Lake Erie to expect there to be at least some
contribution of lake moisture to the column as the front moves
through. In addition to upslope into the U.P. of Michigan and
western New York, higher snow totals can be expected in these
areas.

Finally, over eastern WV, amounts will likely be the highest in=20
the region and WPC probabilities for at least 4 inches of snow are=20

70%, especially above 2000ft. Considerable upslope flow with

northwesterly winds orthogonal to the Appalachians should wring out
the most atmospheric moisture, resulting in the greatest snow
totals here, hence the highest probabilities.

In the wake of the Arctic front, a blast of bitterly cold air will
encompass much of the Northeast heading into the weekend. For more
details, please reference the Extreme Cold Key Messages in the=20
link provided below.

Fracasso/Wegman



...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!-L09wy298h8p0HixTwZRXJh9yemxGI5nIpYl1RfnPrfk3= P4EYhRUXRbBhtoQEcTsBOik16JFMlJIR31mdQRa5gP9iBg$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 050819
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
319 AM EST Thu Feb 5 2026

Valid 12Z Thu Feb 05 2026 - 12Z Sun Feb 08 2026


...The Carolinas...=20
Day 1...

A deep shortwave trough will track across the northern Gulf and
then off the Florida coast through this aftn. This will help
strengthen secondary low pressure off the coast of the Carolinas,
with some lingering moisture extending back onshore, at least
through the morning. However, forecast soundings indicate that
pronounced dry air above the surface will inhibit much in the way
of precipitation. However, what does fall, will occur in a sub-
freezing column, leading to a continuation of very light freezing
rain or freezing drizzle for a few hours after 12Z across the
eastern Carolinas. This is reflected by WPC probabilities that
indicate a 10-30% chance (locally 50% chance) of more than 0.01" of
ice, highest from Cape Fear through the Outer banks.


...Great Lakes, Central Appalachians, Northeast, Mid-Atlantic...=20
Days 1-3...

A fast moving shortwave diving out of Manitoba will race southeast
today, reaching the Mid-Atlantic states by Friday morning. This
lead impulse will be followed almost immediately by a second, more
strung out, shortwave, with this secondary impulse responsible for
driving a strong arctic cold front southward beneath it. This
secondary impulse will help develop a surface wave of low pressure
across Upstate NY Friday evening, with this low scooting rapidly
eastward to off the New England coast by the end of D2. The lead
cold front will trail off this low, with a secondary reinforcing
surge of arctic air occurring Saturday behind a secondary front.

Together, these features will result in an extended period of
moderate ascent, but in an environment with normal to below normal
PWs on the sharpening NW flow. Although the moisture will be
modest, the forcing will be sufficient to wring out snowfall across
the area, although most accumulation will be very light. There may
be a few exceptions:

1) Upslope snow into the Central Appalachians. This is expected
behind the first cold front beginning Friday aftn and then
intensifying Friday night before waning Saturday evening.
Intensifying N/NW flow will become quite strong and direct into the
terrain, with the cooling column providing a deepening DGZ into
which this ascent will maximize. Although atmospheric moisture is
modest, this flow will direct at least some Great Lakes enhanced
moisture to improve the potential for heavy upslope snowfall.
Initially, Froude numbers Friday and Friday night suggest critical=20
or blocked flow indicating the heaviest snowfall will be along or=20
just upwind of the Appalachians crests, but as flow becomes=20
unblocked on Saturday, more snow may spill over towards the east.=20
Still, the heaviest accumulations are likely in the higher terrain=20
and upwind areas, where WPC probabilities for the entire event=20
suggest a high risk (>70% chance) for at least 8" of snow, with=20
locally 12+" possible (30% chance).

The increasing W/NW flow behind the arctic front will also support
some enhanced lake effect snow (LES), especially in the favored=20
more N/NW snow belts south of Lake Ontario and Lake Superior. LES
is not expected to be extremely heavy or prolonged, but WPC
probabilities indicate a 70-90% chance for at least 4" south of=20
Lake Ontario, and a 30-50% chance across the eastern U.P. of=20
Michigan.

Finally, as a surface low strengthens well offshore and east of=20
the Mid-Atlantic states, increasing NW flow with a potential=20
inverted trough will focus some moisture and ascent across eastern=20
New England from near Portland, ME southward to Cape Cod, MA. The=20 combination of onshore flow and ocean effect snow combined with the
potential focused inverted trough may enhance snowfall along the=20
coast. The intensity of this snowfall is still quite uncertain as=20
most of it is early D3, but these inverted troughs can sometimes=20
pivot favorably for locally much heavier snowfall. Confidence is=20
modest at this time range due to wide variations in the models, but
current WPC probabilities indicate a 50-70% chance for at least 4"
of accumulation from Cape Ann southward through Cape Cod,=20
including the Boston metro area.

Finally, although not expected to be widespread, scattered snow
squalls are possible along the arctic front as it digs southward
Friday night into Saturday across the Northeast. Any convective
snow showers or squalls that develop will contain brief heavy snow
rates and strong winds, leading to hazardous travel.

Extremely cold temperatures this weekend have also prompted the
issuance of Key Messages related to this event. Those are linked
below.


Weiss


...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!9APqMvp9Avm9tP_63VeqcPXrzpjBn4ND1yCgQrSuQdPno= TECi6gsEfU5JgOPvZFmrGY8NS2tW8VKC-qRNjuSxNNPVTI$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 051918
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
218 PM EST Thu Feb 5 2026

Valid 00Z Fri Feb 06 2026 - 00Z Mon Feb 09 2026


...Great Lakes, Central Appalachians, Northeast, Mid-Atlantic...=20
Days 1-3...

A deep core low persists north of Hudson Bay through this weekend
with a focused shortwave trough plunging south from Manitoba
tonight, crossing the Great Lakes Friday, before deepening as it
pushes off the Mid-Atlantic Saturday. Rapid surface low development
is expected well east of New England on Saturday as surface high
pressure builds over the Upper Midwest, forming an intense pressure
gradient across the Northeast. A notable surge of Arctic air is
expected Friday night across the Northeast.

Extremely cold temperatures this weekend are discussed further in
Key Messages which are linked below.

The NW flow behind this shortwave will have ascent, but the
continental air and mostly ice covered Great Lakes will limit snow
rates across the Midwest. However, this NW flow will have
topographic enhancement over the central Appalachians Friday
afternoon/evening where rates will locally reach 1"/hr. The arctic
surge over this area is overnight Friday with powerful, potentially
damaging wind gusts as precip rates decrease. Day 1.5 snow probs
for >6" are 40-80% from the western edge of MD down the Allegheny
Highlands into western VA as well as the higher Apps along the
NC/TN border.

As the surface low strengthens and the whole system becomes
develops well off the Mid-Atlantic coast on Saturday, increasing=20
NW flow over an inverted trough will focus some moisture and=20
ascent across New England (outside of Maine).=20
Then on Saturday night there is potential for a focused snow band
to develop near of over Cape Cod which would have ocean
enhancements. As of now Day 2 snow probs for >4" are 40-60% for the
southern shore of Lake Ontario, along the spine of the Green Mtns,
and generally 30% over eastern Mass down through Long Island.
Values for >4" then peak around 40% over Cape Cod for Day 2.5.=20

Finally, although not expected to be widespread, scattered snow
squalls are possible along the arctic front as it digs southward
Friday night into Saturday from New York state down through central
WV. Any convective snow showers or squalls that develop will=20
contain brief heavy snow rates and strong winds, leading to=20
hazardous travel.


...Northwest...
Day 3...

Low pressure pushing northeast into the Gulf of Alaska Saturday
directs an elevated plume of moisture through the Pacific Northwest
Saturday afternoon through Sunday. Snow levels on the Cascades=20
rise to 6000 in WA and 7000ft in OR Saturday afternoon before
dropping to 5000ft in WA Sunday in moderate precip rates. Day 3
PWPF for >6" are 40-80% for the Cascade Volcanoes (above key
mountain passes) and the massif around North Cascades NP.


Jackson



...Cold Key Messages are in effect and linked below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!7KI4dATxiwGQnZk853B_9AzlywkL5ZjkFRAIwG6I2X03r= r6vHEFHnXsemfiTESuFux8NmHZX027MEkGNOGzSd9PYYDg$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 060829
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
329 AM EST Fri Feb 6 2026

Valid 12Z Fri Feb 06 2026 - 12Z Mon Feb 09 2026


...Great Lakes, Central Appalachians, Northeast, Mid-Atlantic...=20
Days 1-2...

Guidance continues to indicate a period of extreme cold will plague
the Northeast, Central Appalachians, and Mid-Atlantic states this
weekend before finally relaxing next week. For this extreme cold,
Key Messages have been issued which are linked below (Key Messages
1).

The driver of this cold will be a sharpening shortwave trough
digging across the Great Lakes today and then amplifying as it
pushes off the Mid-Atlantic coast Saturday. This should become a
closed low south of New England, with the overlap of LFQ diffluence
in a strengthening downstream jet streak with the strong height
falls at 500mb leading to a rapidly deepening surface low well
offshore. While this surface low itself will be too displaced from
the coast to bring notable weather impacts, its pressure gradient
will help enhance northerly winds across the region, driving an
arctic cold front southward, while an inverted trough pivots near
eastern New England Saturday before moving offshore. This will
result in three areas of potential heavy snowfall through Saturday.

1) Central Appalachians: the shortwave itself will cross the
Central Appalachians Friday morning into the afternoon, pushing the
strong front southeast beneath it. While some synoptic ascent into
a modestly moistening column will result in widespread light snow,
the heaviest accumulations are likely to occur within post-frontal
upslope ascent. This lift should maximize into the lower portions
of the deepening DGZ, and as moisture from the Great Lakes gets
advected southward, this will result in periods of heavy snowfall
for which the WPC prototype snowband tool suggests will exceed
1"/hr at times. The heaviest snowfall is expected Friday evening
through early Saturday morning before the column dries, and WPC
probabilities indicate a high risk (>70% chance) of at least 6
inches of snow across the higher terrain of WV, with locally 10+
inches possible, and at least 4 inches (50-70% chance) extending
from the Laurel Highlands down into the higher terrain of NC/TN.

2) Great Lakes: Although ice cover across the Lakes has increased
dramatically the past few weeks, the intense CAA behind this front
will still support some lake effect snow (LES) across the open
waters, especially south of Lake Ontario and Lake Superior D1. The
intensity of this snowfall should be somewhat muted, but WPC
probabilities for 4+ inches reach as high as 70-90% south of Lake
Ontario, with slightly lower probabilities across the eastern U.P.
and northwest L.P. of MI.

3) Eastern New England: The most challenging aspect of this
forecast is what happens across eastern New England, especially
along the coast from near Portland, ME, through Boston, MA, and
onto Cape Cod. Strong N/NE winds within the CAA should produce
ocean enhanced snowfall (OES) especially for Cape Ann and Cape Cod,
with some enhancement possible anywhere along the coast from Boston
southward. At the same time, the guidance, while very different in
its spatial positioning, all show some degree of an inverted trough
pivoting across the region, with low-level convergence aiding in
ascent. While there is uncertainty in the placement, and this
should come into better focus as we get more steadily into the
high-res windows, there is nearly uniform agreement of this
occurring, and with some fgen efficiently intersecting the lowering DGZ,
this will likely result in periods of heavy snowfall. Despite the=20 uncertainty, WPC probabilities have crept upwards to above 50% for
4+ inches from near Portsmouth, NH south to Boston and Plymouth,
MA,but some locally higher amounts are probable as reflected by a=20
lot of spread in the WSE plumes for coastal areas.

Finally, although not expected to be widespread, scattered snow=20
squalls are possible along the arctic front as it digs southward=20
Friday night into Saturday from New York state down through central
WV and into New England. Any convective snow showers or squalls=20
that develop will contain brief heavy snow rates and strong winds,=20
leading to hazardous travel.


...Pacific Northwest and Northern Rockies...=20
Day 3...

A shortwave emerging from the Northern Pacific will track eastward,
moving onshore WA/OR Sunday night and then deamplifying as it
approaches the Northern Rockies by the end of the forecast period.
Downstream of this impulse, a period of enhanced moisture advection
will occur, both in response to modest WAA as well as a weak upper
jet streak pivoting into Canada. Together, this will drive IVT
onshore in a corridor from OR through the Northern Rockies, which
has a high probabilities (>80%) of exceeding 250 kg/m/s. The
duration of this IVT is likely to be limited, and the corresponding
WAA will surge snow levels up to 5000-6000 ft before falling the
latter half of D3 (due to CAA behind an accompanying cold front)
back down to 2000-3000 ft. However, most of the precipitation
should occur within the warm plume, and this is reflected by WPC
probabilities indicating a high risk (>70% chance) for at least 4
inches of snow for the higher terrain of the Cascades and into=20
parts of the Northern Rockies near Glacier NP, and into the=20
Sawtooth/Salmon River ranges.

Weiss



...Winter Storm Key Messages are in effect. Please see current=20
Key Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!7nWiQeLPwPN72vtw9t41hN6JrVIti4KCD6SQD2TX7WWPP= ZZgrW4eB3_Vk4vl1tNvlEpBd3HXuZLoyLL7HuFiyW4fumA$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 061933
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
233 PM EST Fri Feb 6 2026

Valid 00Z Sat Feb 07 2026 - 00Z Tue Feb 10 2026


...Great Lakes, Central Appalachians, Northeast, Mid-Atlantic...=20
Days 1-2...

Extreme cold and dangerous wind chills overspreads the Northeast=20
tonight with Key Messages in effect and linked below.

An upper low currently over James Bay gets sheared southeast over
the Northeast tonight on account of a strengthening NWly jet below
a stationary parent low north of Hudson Bay. Surface low pressure
develops early Saturday outside of the 70W/40N Benchmark with an
inverted trough extending from that low up through eastern New=20
England. This movement results in three notable areas of snow.

1) Central/Southern Appalachians: Ongoing upslope snow for the=20 central/southern Apps through this evening with powerful winds
overnight behind the cold front. Not much additional snow is
expected, particularly due to the Great Lakes being mostly ice=20
covered, but blowing snow is certainly a concern.

2) Great Lakes: Spotty lake effect snow will continue into Saturday
for parts of northern MI downwind of open portions of Lake=20
Superior and Michigan.

3) Eastern New England: Strong N/NE winds within the CAA should=20
produce ocean enhanced snowfall (OES) in eastern Mass. At the same
time, the inverted trough pivots across the region with low- level
convergence aiding in ascent. Fgen efficiently intersecting the=20
lowering DGZ will result in narrow corridors of heavy snowfall.=20
Day 1 snow probs for >4" are 40-70% for southern NH down through
Rhode Island.

Snow Squalls: the greatest snow squall threat is this evening over
Ohio and West Virginia west of the Allegheny Front where high=20
winds coincide with frontal banding. This area has had the most=20
notable snow squall parameter values in recent days. Any convective
snow showers or squalls that develop will contain brief heavy snow
rates and strong winds, leading to hazardous travel.
More general snowfall can be expected with the front tonight across
NY state and the Green Mtns.=20


...Pacific Northwest and Northern Rockies...=20
Days 1-3...

A shortwave trough axis crosses the Pacific Northwest Saturday/=20
Saturday night with a second trough crossing late Sunday into
Monday. Enhanced moisture advection spreads inland ahead of these
waves with increasing snow over the Cascades and Northern Rockies.=20=20
Snow levels rise to 6000/7000ft tonight for the WA/OR Cascades with
levels over WA dropping up to 4000ft Saturday night under height
falls. Day 1 snow probs for >4" are 40-70% for the North Cascades
and WA Volcanoes above 6000ft. Day 2 snow probs for >6" are 40-70%
for the higher WA/OR Cascades and the highest northwest MT ranges.
Much of the Northwest gets moderate precip with the second wave,
Day 3 snow probs for >6" are 50-80% for the WA/OR Cascades above
4000ft and across western MT/central and northern ID and northwest
WY ranges.


Jackson



...Cold Key Messages are in effect and linked below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!6KUdSlc3x9gxIvJgJ8CClYrdLr-MkgN3h8WhznNitWZ-i= rLKGoqcAEia_Z2pz_5BOuh2Xqg3C0gJPFrlj7Ux-nuxS00$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 070706
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
206 AM EST Sat Feb 7 2026

Valid 12Z Sat Feb 07 2026 - 12Z Tue Feb 10 2026


...Northeast & Mid-Atlantic...=20
Day 1...

Extreme cold and dangerous wind chills overspread the Northeast=20
tonight and continue through Sunday with Key Messages in effect=20
and linked below.

The combination of an arctic cold front current racing through the
Ohio Valley/Interior Mid-Atlantic will combine with a strengthening
low pressure well offshore to produce extremely cold temperatures
and damaging winds for much of the region, with heavy snow for=20
parts of the area as well.

A shortwave driving the cold front southward will help generate
widespread light snow across New England and Long Island, but total
snowfall amounts are expected to be rather modest. Despite that,
briefly heavy snow rates combined with the rapidly increasing winds
will still result in impacts, especially to travel due to snow-
covered roads and low visibility. The greatest impacts, and likely
more substantial snowfall, is expected from far SW Maine, SE New
Hampshire, and along the eastern Coast of Massachusetts from Cape
Ann to Cape Cod where low-level convergence, onshore flow and
resulting ocean effect snow (OES) and an inverted trough will all
interact to enhance snowfall. There continues to be uncertainty as
to where the heaviest snowfall will occur. However, intense=20
snowfall rates of 1-2"/hr are possible (30-60% chance) thanks to=20
intense ascent into a lowering DGZ within the presence of some=20
instability. WPC probabilities are moderate (50-70%) for 4+ inches=20
from the Seacoast of NH through the Boston metro area, with locally
more than 8 inches possible (10-30% chance) and as reflected by=20
significant spread amongst the WSE plumes.


...Pacific Northwest and Northern Rockies...=20
Days 1-3...

Mid-level trough positioned off the Pacific coast will slowly track
eastward today and Sunday, with the primary trough axis finally
pushing onshore Sunday night as a shortwave lifts onshore near the
CA/OR coast. This shortwave will then continue to track east while deamplifying, reaching the northern High Plains by the end of the
forecast period.

This trough evolution will be accompanied by a modest subtropical
jet streak arcing meridionally downstream to provide overlapping
synoptic ascent. This lift will occur into a moistening column as
persistent SW flow ahead of the shortwave/trough axis will provide
a long duration of IVT exceeding 250 kg/m/s, with IVT max
potentially exceeding 500 kg/m/s (50-60% chance) which will lead to
two rounds of heavy precipitation extending from Oregon through=20
the Northern Rockies. Snow levels within the strongest IVT plume
will be 6000-7000 ft thanks to pronounced WAA, but will steadily
fall to 3000-4000 ft Monday as a cold front, driven by the
aforementioned trough, progresses southeast. This will allow for
heavier and more impactful snow across the Northern Rockies than
what is anticipated in the Cascades due to lower snow levels. 2-day
WPC probabilities indicate the heaviest snow is expected in the
vicinity of Glacier NP in the Northern Rockies where they exceed
70% for 12+ inches, and locally as much as 2 feet is possible in
the highest terrain. Elsewhere, WPC probabilities are high (>70%)
for 8+ inches across the Absarokas and Tetons near Yellowstone NP,
the Blue Mountains of OR, and across the highest peaks of the WA=20
and OR Cascades.



Weiss


...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!4Xa2oHMmm6KfYz7unG9Agh0MhfUQ7fqpY9sRHyH0zmenP= 8OIT453zr1s2_i_RtderGizZjFyR5DPVZVOSXZzX8SPp3g$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 071904
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
204 PM EST Sat Feb 7 2026

Valid 00Z Sun Feb 08 2026 - 00Z Wed Feb 11 2026


...Southeast New England...=20
Day 1...

Ongoing convergent banding over southeast New England will continue
to shunt east as it gets further undercut by the Arctic cold front
which will shift offshore late evening. Remaining snow should taper
off this evening.


...Pacific Northwest and Northern Rockies...=20
Days 1-2...

A trough axis pushes across western WA this evening with the
leading moisture axis maintaining moderate precip rates until the
overnight when they are shunted south. Snow levels on the WA
Cascades decrease from 6000ft to 4000ft tonight under height falls.=20
The primary trough axis pushes onshore the PacNW Sunday evening. This
wave will then continue to track east while deamplifying, reaching
the northern High Plains Monday.

This trough evolution will be accompanied by a modest subtropical
jet streak arcing meridionally downstream to provide overlapping
synoptic ascent. This lift will occur into a moistening column as
persistent SW flow ahead of the shortwave/trough axis will provide
a long duration of moisture advection with two rounds of heavy=20
precipitation extending from Oregon through the Northern Rockies.=20
Day 1 snow probs for >6" are 40-80% for the WA/OR Cascades above
about 5000ft and over the northern Rockies. Day 2 snow probs for

6" are similar to Day 1 for the Cascades, but much greater across

the northern Rockies including 50-90% for the Tetons, Absarokas,
Sawtooths, Bitterroots, and through Glacier NP. Snow tapers off
Monday as the trough axis shifts onto the Plains.


...Sierra Nevada and Great Basin...=20
Day 3...

The next shortwave trough from the Pacific shifts farther south
than more recent ones, reaching the central/northern CA coast late
Monday night, crossing the Great Basin Tuesday night. Snow levels
of 6000 to 7000ft can be expected on the Sierra Nevada with the
early snow Monday night and 5000 to 6000ft Tuesday as the trough
axis approaches. Day 3 snow probs for >6" are 50-80% over the
length of the Sierra Nevada. A welcome sight for skiers and those
with Sierra hydrology interests.


Jackson



...Extreme Cold Key Messages are in effect and linked below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!-BeRRGW9T0baCl--AvirbLAP2kstK75nNVKBxmBURQ_C9= uocuM5i-gTcobPUFZa9ROYAvgzvZ3UZTtfsdeDhIKBI4LY$=20


$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 080719
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
219 AM EST Sun Feb 8 2026

Valid 12Z Sun Feb 08 2026 - 12Z Wed Feb 11 2026


...Pacific Northwest and Northern Rockies...=20
Days 1-2...

A surface cold front will be draped NE to SW from Montana through
Oregon to start the period, lingering from a wave of low pressure
moving across Canada. As this cold front wavers Sunday, a
shortwave trough will emerge from the Pacific and cross northeast
into the Pacific Northwest, reaching the Northern Rockies Monday
evening while deamplifying and shearing out into the westerlies.
This will result in a secondary wave of low pressure developing
along the front which will finally kick the front southeast and out
of the region.

Forcing for ascent will intensify as this shortwave lifts
northeast, as mid-level divergence and heights falls interact atop
the boundary, and work in tandem with a zonally oriented but
intensifying jet streak arcing into the Northern Plains. This
synoptic lift atop the corresponding moisture (via strengthening
but still modest IVT) will result in a stripe of precipitation,
with snowfall expected in the higher terrain. Snow levels will be
falling through the period as the cold front and height falls
progress E/SE, reaching as low as 3000-4000 ft before precip winds
down by Tuesday morning. 2-day WPC probabilities indicate a high
potential (>70% chance) for at least 8 inches in the higher terrain
of the Cascades, as well as across the Blue Mountains, and much of
the terrain of the Northern Rockies of ID/western MT/northwest WY.
Locally 1-2 feet is possible.


...Sierra Nevada and Great Basin...=20
Days 2-3...

A closed mid-level low west of California will gradually translate
eastward, potentially coming onshore northern California by the end
of the forecast period. The progression of this low will result in
increasing ascent through height falls/mid-level divergence into
CA. At the same time, a subtropical jet streak will intensify
downstream of this trough axis, strengthening to 130 kts and
placing the favorable LFQ diffluent region over CA and into the
Great Basin, aligning with the strongest height falls. Moisture
advection will spread onshore beneath modest IVT (40-60% chance of
at least 250 kg/m/s) but this will be sufficient to spread heavy
precipitation into the region. With snow levels expected to be
generally 6000-7000 ft, the heavy snow should be confined to the
Sierra and higher terrain farther east (Ruby mountains of NV and
into the Uintas, but at least light snow will spread across much of
the Great Basin above 6000 ft, rare for what has been an
exceptionally dry winter so far, and likely welcome for most of the
region. Current WPC probabilities indicate a high chance (>70%) for
more than 8 inches in the high Sierra, with locally more than 12
inches possible (30-50% chance). Farther east, WPC probabilities
indicate a low risk (30%) for 6+ inches in the Ruby Mountains and
parts of the Uintas.


...Northeast...
Day 3...

A clipper-type low will drop out of Ontario and cross Upstate New
York and New England Tuesday evening/Tuesday night. The clipper
itself is not impressively strong, but will be preceded by a period
of moderate WAA which will help expand a shield of snowfall with
moderate snow rates from NY through central/northern New England.
As the clipper dives through the area after 00Z Wednesday, it will
be followed additionally by some upslope ascent into the
Adirondacks and Greens to enhance snowfall potential. Most of the
snow should be of moderate intensity and limited duration (6-12
hours), but where the WAA snow combined with post-system upslope
snow, a few inches of accumulation is likely. This is reflected by
WPC probabilities that indicate a 50-70% chance of at least 4
inches in the Adirondacks and Greens.


Weiss



...Extreme Cold Key Messages are in effect. Please see current Key
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_1.png__;!!DZ3fjg!8eF8W36sZqTxakcMe0UhPFhNgT5PYu0eE845MF0JBX84Q= a-TSjewl7qNUuyG1gEbVE4ah4GKia6xdYgvnsASn-AS6ng$=20



$$

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 082034
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
334 PM EST Sun Feb 8 2026

Valid 00Z Mon Feb 09 2026 - 00Z Thu Feb 12 2026


...Pacific Northwest through Northern Rockies...
Day 1...

A shortwave trough crosses the Pacific Northwest this evening and
the northern Rockies Monday. Much of the moisture is ahead of this
trough axis with moderate to heavy rates stretches from far
northern CA through OR and western MT. Snow levels are initially
high, around 7000ft, over northern CA through ID/southern
MT, with a gradient down to 4000ft just a couple hundred miles
north. Height falls from the trough axis will lower tonight to
around 4000ft across the snow zone (3000ft where the 4000ft levels
currently are). Day 1 snow probs are 50-80% for >6" across the
Sawtooths through Bitterroots, and all western MT and northwest WY
ranges. These values are generally 30-70% for the WA/OR Cascades
above about 5000ft. Ridging behind the trough axis will provide a
fairly clean cut off for this mountain snow fall by late Monday.


...Sierra Nevada to Wyoming...
Days 2-3...

A closed mid-level low will approach central California from the
west on Tuesday before stalling over northern CA through much of
Wednesday as a reinforcing trough digs around it well offshore.
Strengthening left exit jet dynamics through this time will enhance
lift for the onshore flow that rises over the Sierra Nevada. Energy
sheds east from the upper low Tuesday night bringing much needed
precip to the Great Basin and central Rockies through midweek.

Snow levels will be at or just below 7000ft along the Sierra Nevada
on Tuesday in the onshore flow, dropping to around 6000ft Tuesday
night under height falls. Great Basin/Rockies snow levels will
generally remain 6000-7000ft through midweek.

Day 2 snow probs for >6" are generally 30-60% along the Sierra
Nevada (and Lassen Peak) for the initial snow on Tuesday. The bulk
of Sierra snow falls Tuesday night/Wednesday with Day 3 snow probs
for >12" generally 30-60% between 6500ft and 8000ft (and 80%
above). High-end advisories are raised for the Sierra Nevada. There
is risk for localized enhanced snowfall that would warrant targeted
warnings, particularly if rates can pick up around 7000ft
elevation. Farther east, Day 3 snow probs for >6" are 30-70% on the
highest NV ranges (such as Ruby), the highest Uinta, and
particularly for the Tetons and Wind Rivers.


...Northern Great Lakes and Northeast...
Days 2/3...

The shortwave trough crossing the Pacific Northwest tonight reaches
the northern Great Lakes Monday night where it could merge with
northern stream energy over Ontario and promote decent
development/warm air advection precip over the northern Great
Lakes. This would be a wintry mix on the southern end with some
snow banding potential either over Lake Superior or possibly into
the eastern U.P. Day 2 snow probs for >4" are 20-50% over the far
northern L.P. and eastern U.P. while there are 40-70% probs for

0.01" ice from the WI/MI border ESE across the L.P.

By Tuesday afternoon the warm air advection plume shifts through
Upstate NY with the warm nose great enough for a wintry mix which
should tend toward freezing rain given how cold it has been there
lately. Day 2.5 snow probs for >4" are 30-70% over the Tug Hill,
Adirondacks, and Greens while 0.01" ice probs are 30 to 50% for
northern PA through southern NY and east through greater NYC.

Coastal low development aids snow banding into eastern Maine on
Tuesday night into Wednesday. Day 3 snow probs for >4" are 30-50%
along the entire Maine Coast.


Jackson



$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 090734
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
234 AM EST Mon Feb 9 2026

Valid 12Z Mon Feb 09 2026 - 12Z Thu Feb 12 2026


...Pacific Northwest through Northern Rockies...
Day 1...

A shortwave trough crossing the area will be positioned atop the
interior Northwest to start the period, and then translate rapidly
eastward through D1. This feature will likely shear out into the
westerlies as it advects into the High Plains in response to rapid
ridging building in its wake, but there has been a subtle trend of
increased amplitude of this feature tonight. This shortwave will
work effectively with an intensifying upper jet streak to overlap
mid-level height falls with LFQ diffluence, leading to sufficient
ascent to produce a wave of low pressure along a cold front south
of the region.

Additionally, this jet streak will result in increasing mid-level frontogenesis, especially within the 700-500mb layer, which will
produce impressive omega directly into the DGZ. Although ascent
will be temporally modest, cross-sections indicate a high threat
for CSI within any snow bands that develop, and this could (30-60%
chance) produce 1-2"/hr snowfall rates. The heaviest snowfall is
likely in the terrain of the Absarokas and near Yellowstone NP due
to upslope enhancement, but anywhere across southern MT and
northern WY could see bands of heavy snowfall which will accumulate
rapidly despite marginal thermals in the low- levels. The high-res
guidance has trended upward significantly, as have many of the
globals, so confidence has increased in significant snowfall
accumulations, which is now reflected by WPC probabilities that
indicate a high risk (>70% chance) for at least 4 inches, with more
than 12 inches possible in the higher terrain including the Lewis
Range and Tetons.


...Sierra Nevada to the Central Rockies...
Days 2-3...

A closed mid-level low will approach central California from the
west on Tuesday before slowly filling into an open, positively
tilted trough Wednesday as secondary vorticity energy digs towards
Baja. This slow evolution will result in pronounced S/SW flow
aloft, which will combine with a strengthening jet streak to spread
moisture onshore CA and then expand eastward towards the Central
Rockies by late Wednesday. This prolonged, albeit relatively
modest, moisture plume/IVT will bring much needed precip to the
Great Basin and central Rockies through midweek.

Snow levels will be at or just below 7000ft along the Sierra Nevada
on Tuesday in the onshore flow, dropping to around 6000ft Tuesday
night under height falls. Great Basin/Rockies snow levels will
generally remain 6000-7000ft through midweek.

2-day snow probabilities from WPC suggest a near certainty (>90%)
of at least 8 inches across much of the Sierra with locally as much
as 2 feet possible (30% chance) in the higher Sierra. Additional
snowfall totals exceeding 8 inches are possible (50-70%) for parts
of the Uintas, Colorado Rockies, and northern CA ranges.


...Northern Great Lakes and Northeast...
Days 1-3...

A closed mid-level low will elongate and track from the Northern
Great Lakes to across New England mid-week, exiting to the Gulf of
Maine by Thursday morning. This upper feature will be accompanied
by an extended vorticity lobe on its south side, helping to produce
strong ascent through height falls/PVA across the region. As this
develops, pronounced warm air advection (WAA) will develop to its
south as a surface low /clipper type/ races southeast beneath the
upper trough. This will produce two rounds of ascent: first with
the intensifying WAA south of the surface low, and then second with post-clipper CAA/upslope flow.

While the ascent within the WAA will be impressive, it will also be
of short duration, generally 6-12 hours, so although snowfall rates
will likely be intense (50-70% chance of 1+"/hr), the total
snowfall accumulations will be tempered as reflected by WPC
probabilities that are around 30% for 4+ inches across the U.P. of
MI D1, and then 30-70% on D2 for Upstate NY and northern/central
New England. Despite that, some more significant snowfall
accumulations are likely across the Tug Hill Plateau, the
Adirondacks, and the Greens where a combination of CAA for lake
effect snow (in the Tug Hill) and upslope snow (Adirondacks and
Greens) will lengthen the duration of accumulating snowfall. In
these areas, locally more than 8 inches of snow is possible
(10-30%, highest across the Tug Hill Plateau).

Finally, as the closed low moves into the Gulf of Maine, a surface
low will deepen offshore in response. While direct impacts from
this surface low are not expected to be significant, the guidance
is hinting at a lingering inverted trough pivoting back across
coastal Maine Wednesday. These inverted troughs can sometimes lead
to sneaky-heavy snowfall accumulations, so although current WPC
probabilities are around 50-70% for 4+ inches of snow, this will
need to be monitored for any upticks as the event gets closer.


Weiss


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 091952
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
252 PM EST Mon Feb 9 2026

Valid 00Z Tue Feb 10 2026 - 00Z Fri Feb 13 2026


...Sierra Nevada to the Central Rockies...
Days 1-3...

A mid-level low in the northeast Pacific just north of a 150kt jet
streak this evening will move southeastward then eastward into
NorCal tomorrow night. This will direct a modest plume of moisture
into the Sierra with snow levels initially around 7000ft then
dropping to around 6000ft. Snow could fall at >1"/hr tomorrow night
in the higher Sierra (>8000ft) then subside through Wednesday. WPC probabilities for at least 8 inches of snow are >50% above 6000ft
or so with >18" likely (<80%) above 8000ft.

The system will continue eastward as the upper jet strengthens
over the Great Basin to central Rockies as the upper trough remains positively-tilted. Moisture will continue to funnel from the sub-
tropics into the Four Corners region (>90th percentile) on
southwesterly flow. Snow levels will waver around 6000-7000ft with
modest amounts expected in an area that has seen very little snow
this season. WPC probabilities for at least 8 inches of snow are

50% above 7000ft or so in UT and 8000ft in WY. Snow will linger

longest over the CO Rockies through Thursday as the moisture plume
stalls there as a result of a second shortwave trailing the lead
system, maintaining SW flow through the end of this period. WPC
probabilities for at least 8 inches of snow are >50% above 10,000ft
or so in CO.


...Northern Great Lakes and Northeast...
Days 1-3...

A progressive closed mid-level low will elongate and track from
the Northern Great Lakes to across New England mid-week,
translating into the Gulf of Maine on Wednesday. This upper feature
will be accompanied by an extended vorticity lobe on its south
side along the occlusion, helping to produce strong ascent through
height falls/PVA across the region. As this develops, pronounced
warm air advection (WAA) will develop to its south up and over a
surface warm front across the Mid-Atlantic. Lead WAA- drive
precipitation will arrive over northern NY/New England tomorrow
evening followed by the frontal passage. CAA will ensue with some
lake effect and upslope snow across the region Wednesday through
Thursday.

Quasi-zonal flow will limit precipitation duration, but CAM
guidance still indicates a window of >1"/hr rates (50-80% chance)
over the Adirondacks, northern and central VT/NH, and into
southwest Maine between 21Z Tue and 04Z Wed (from west to east)
ahead of the occlusion and as it translates into the Gulf of Maine.
Behind the front, NW flow will support widespread multi-banded
lake effect snow downwind of all Great Lakes (less from mostly all-
frozen Erie) that will be enhanced at times from trailing vort
maxes streaming in from the NW.

WPC probabilities for at least 4 inches of snow for the event are

50% over southwestern NY, central NY into the Adirondacks/North

Country, northern VT/NH and across much of Maine except for far
northern areas (removed from the higher QPF). Some favored upslope
areas could see in excess of 8 inches of snow, especially over the
Tug Hill into the Green Mountains.

Finally, as the closed low moves into the Gulf of Maine, a new
surface low down the occlusion will deepen offshore in response.
While direct impacts from this surface low are not expected to be
significant, the guidance (e.g., NAMnest, CMCreg) is hinting at a
lingering inverted trough pivoting back across coastal Maine
Wednesday afternoon/evening. These inverted troughs can sometimes
lead to sneaky-heavy snowfall accumulations. WPC probabilities for
at least 8 inches of snow between Bangor and Eastport are 25-45%
right now, and may change pending more hi-res guidance.


Fracasso/Weiss


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 100716
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
216 AM EST Tue Feb 10 2026

Valid 12Z Tue Feb 10 2026 - 12Z Fri Feb 13 2026


...Sierra Nevada to the Central Rockies...
Days 1-3...

Mid-level low over the Pacific will gradually pivot eastward
towards northern CA through Wednesday, lingering across the state
as it slowly fills. Immediately downstream of this feature, a
subtropical jet streak will intensify, especially late this evening
into Wednesday morning, reaching towards 150 kts as it pivots over
central CA. This upper jet will provide favorable LFQ diffluence
overlapping the most significant height falls for pronounced
synoptic ascent, while additionally transporting Pacific moisture
onshore CA before spreading into the Great Basin and Central
Rockies. The evolution of this synoptic pattern suggests that SW
flow downstream of the primary trough axis will support prolonged
moisture advection, which is reflected by IVT probabilities from
both the GEFS and ECENS exceeding 90% for 250 kg/m/s for around 24
today into Wednesday. This moisture will be wrung out by the
significant deep layer ascent (aided by upslope flow especially
across the Sierra) to produce heavy snowfall above generally
6000-7000 ft, with the most intense snowfall rates (2+"/hr
according to the WPC prototype snowband tool) occurring across the
Sierra tonight into Wednesday. WPC probabilities across the Sierra
are high (>70%, 2-day totals) for more than 12 inches in the high
SIerra, but widespread 8+ inches is likely (>70%) for the breadth
of the Sierra and into parts of the northern California terrain.

As the system continues eastward and the upper jet strengthens
over the Great Basin to central Rockies, moisture will continue to
funnel from the sub-tropics into the Four Corners region on
southwesterly flow. Snow levels will waver around 6000-7000ft with
modest amounts expected in an area that has seen very little snow
this season. WPC probabilities for at least 8 inches of snow are

50% above 7000ft or so in UT and 8000ft in WY, highest over the

Uintas and Wind Rivers/Tetons. Snow will linger longest over the
CO Rockies through Thursday as the moisture plume stalls there as a
result of a second shortwave trailing the lead system, maintaining
SW flow through the end of this period. WPC probabilities for at
least 8 inches are high for 8+ inches across much of the highest
terrain of the Colorado Rockies, with a local maximum above 12
inches expected across the Park Range.


...Eastern Great Lakes and Northeast...
Days 1-2...

A clipper-type low will dig southeast from Ontario through New
England today, exiting into the Gulf of Maine late tonight. This
clipper will be driven primarily by a closed, but weakening, mid-
level low tracking atop it, with elongated vorticity to its south
producing additional ascent. As this upper low shifts off New
England, it will interact with an occlusion well off the coast,
helping to rapidly deepen a surface low over the Atlantic. This
synoptic evolution will result in 3 areas of moderate to heavy
snowfall:

1) Pronounced warm-air-advection (WAA) developing south of the
clipper will surge northeast atop a warm front across the Mid-
Atlantic and into the Northeast. This will create an expanding
shield of precipitation, and although some light mixed
rain/snow/freezing rain is expected over the northern Mid-Atlantic,
much of this precipitation should fall as snow across New England
and Upstate New York. The snow that occurs will likely be heavy at
times within a WAA band, likely exceeding 1"/hr (60-90% chance),
with the short temporal duration limiting the total snowfall.
Still, impactful snow is likely this evening and tonight spreading
from west to east.

2) Post-clipper cold-air-advection (CAA) will become impressive in
the wake of the low. This will create increasing lake effect snow
(LES) despite significant ice cover now over the Great Lakes, as
well as intensifying upslope snow into the terrain of the
Adirondacks and Greens. Very dry air beneath the subsidence
inversion will impinge into the DGZ from above during this time, so
that will act to limit snowfall intensity within the upslope
regime, but additional accumulations are likely. LES will also be
somewhat modest, and focused east of Lake Ontario into the Tug Hill
and then southeast towards the Finger Lakes region, as well as far
SW NY east of Lake Erie.

WPC probabilities for 2+ inches of snow are high (>70%) for much
of northern Upstate NY, as well as central/northern New England.
However, the more substantial snowfall is likely in the higher
elevations where WPC probabilities suggest a high risk (>70%) for
at least 4 inches in the Adirondacks, Greens, and Whites, with
locally as much as 8 inches possible. For the LES areas, WPC
probabilities are moderate (50-70%) for least 4 inches. For the
freezing rain, a swath of moderate probabilities (>50%) exists for
0.01+" of ice from the Finger Lakes through the Poconos and into
southern New England and Long Island. Although amounts should be
less than 0.1"

3) Finally, as the surface low deepens rapidly offshore and near
Nova Scotia Wednesday, the guidance continues to suggest a
lingering inverted trough will pivot near the coast of Maine. Where
this occurs, additional ascent will be locally impressive, leading
to the potential for several inches of additional snowfall. These
inverted troughs can sometimes lead to sneaky-heavy snowfall
accumulations, so while WPC probabilities are moderate for 6+
inches (50-70%), locally higher totals are possible as reflected by
significant spread in the WSE plumes along the coast of Maine.

Weiss


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 101945
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
245 PM EST Tue Feb 10 2026

Valid 00Z Wed Feb 11 2026 - 00Z Sat Feb 14 2026


...Sierra Nevada to the Central/Southern Rockies...
Days 1-3...

Closed low just west of NorCal will push eastward tonight as a
surface cold front moves toward/into the Sierra. A trailing upper
low to its northwest will take a longer route along its southwest
side and eventually move into the Southwest/northeastern Mexico
late in the forecast period. The trough axis will remain
positively-tilted as the two entities act to slow the overall
progress of the flow resulting in an unsettled period but bounded
by two periods of modest to perhaps heavier precipitation. Moisture
amounts and flux anomalies are modest, but accumulations will be
aided by favorable upslope SW flow. Snow levels will vary between
6000-7000ft over the Sierra and snow rates will likely be >1-2"/hr
at times tonight/early Wednesday per the 12Z CAM guidance. WPC
probabilities for at least 12 inches of snow are >50% above 6500ft
or so. Two-day totals may exceed 2ft in the highest elevations.

Farther downstream, moisture tied back to the subtropics will
continue to increase over the Great Basin to the central Rockies
tonight as the upper jet accelerates over the region and PVA
increases. Snow levels around 6000-7000ft will favor mountain snow
to areas that have seen very little this season. WPC probabilities
for at least 8 inches of snow are >50% above 7000ft or so in UT and
8000ft in WY, highest over the Uintas and Wind Rivers/Tetons, but
with modest totals overall. Snow will linger longest over the CO
Rockies through Thursday as the moisture plume stalls due to the
trailing upper low. WPC probabilities for at least 8 inches of snow
are >70% above 10,000ft or so in CO. By Friday, as that system
finally moves over northeastern Mexico, moisture and height falls
will lead to snow over the southern Rockies (southwestern CO and
northern NM) as well as into AZ (Mogollon Rim/White Mountains).
Amounts will be light except for the highest elevations, generally
above 10,000ft.


...Eastern Great Lakes and Northeast...
Days 1-2...

A strong clipper-type low will move through New England tonight
and stretch out to the Gulf of Maine by tomorrow morning. This
clipper will be driven primarily by a closed, but weakening, mid-
level low tracking atop it, with elongated vorticity to its south
producing additional ascent. The elongated vorticity will favor a
jump in the surface low down the occlusion and into the Gulf of
Maine by 12Z Wed which will then start to rapidly deepen as it
pulls away into Atlantic Canada. The storm will come in three
distinct parts related to winter weather:

1) Pronounced warm-air-advection (WAA) developing south of the
clipper this evening will surge northeastward atop a warm front
across the Mid-Atlantic and into the Northeast. This will create an
expanding shield of precipitation, and although some light mixed rain/snow/freezing rain is expected over the northern Mid- Atlantic
into the NYC metro area, much of this precipitation should fall as
snow across New England (esp north of I-90) and Upstate New York.
The snow that occurs will likely be heavy at times within a WAA
band, likely exceeding 1"/hr (60-90% chance per the 12Z HREF), with
the short temporal duration limiting the total snowfall. Still,
impactful snow is likely this evening and tonight spreading from
west to east with the highest totals over the Adirondacks and
central/northern New England.

2) Post-clipper cold-air-advection (CAA) will become impressive in
the wake of the low. This will create increasing lake effect snow
(LES) despite significant ice cover now over the Great Lakes, as
well as intensifying upslope snow into the terrain of the
Adirondacks and Greens. Very dry air beneath the subsidence
inversion will impinge into the DGZ from above during this time, so
that will act to limit snowfall intensity within the upslope
regime, but additional accumulations are likely. LES will also be
somewhat modest and multi-banded, focused east of Lake Ontario into
the Tug Hill and then southeast through the Finger Lakes region
into far SW NY east of mostly frozen Lake Erie (likely aided from
Lake Huron and/or Georgian Bay).

WPC probabilities for at least 4 inches of snow are >50% for the
western Adirondacks as well as central/northern New England and
much of Maine, especially outside the lower elevations. For the
higher elevations, WPC probabilities for at least 6 inches of snow
are >50% over the Greens, Whites, and the Central Highlands in
Maine with locally as much as 8 inches possible. For the LES areas
in NY, WPC probabilities are moderate (40-70%) for least 4 inches
with higher local accumulations. For the freezing rain, a swath of
moderate probabilities (40-70%) exists for 0.01+" of ice from the
Finger Lakes/Southern Tier down I-88/81 through the Poconos
eastward along I-80 through northern NJ and into southern New
England and perhaps Long Island. Amounts should be less than 0.10"
but any freezing rain can be hazardous to travel, especially
overnight.

3) Finally, as the surface low deepens rapidly offshore and near
Nova Scotia Wednesday, the guidance continues to suggest a
lingering inverted trough that will pivot near the coast of eastern
Maine. Where this occurs, additional ascent will be locally
impressive, leading to the potential for several inches of
additional snowfall. These inverted troughs can sometimes lead to
sneaky-heavy snowfall accumulations, but WPC probabilities for at
least 8 inches of snow are moderate (40-70%) around Eastport.
Locally higher totals are possible as reflected in some rather
robust 12Z CAM members along the coast of Maine.

The probability of significant icing across the CONUS is less than
10 percent.


Fracasso/Weiss


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 110625
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
125 AM EST Wed Feb 11 2026

Valid 12Z Wed Feb 11 2026 - 12Z Sat Feb 14 2026

...Eastern Great Lakes and Northeast...
Day 1...

The strong clipper-type low will continue to push east off the New
England coast as the driving shortwave aloft races to the
southeast. The vorticity accompanying this shortwave will help
develop secondary low pressure along a triple point well offshore
(near Nova Scotia), with this secondary low deepening as it pulls
away. Although this low should be well too far east to bring any
direct impacts to the Northeast, the guidance continues to indicate
an inverted trough will pivot cyclonically around the low, bringing
enhanced ascent to the coast of Maine, resulting in bands of heavy
snow. Some uncertainty continues with the exact placement of these
bands, but the high-res is quite agreeable in their occurrence.
This suggests that while WPC probabilities for 4+ inches are just
30-50% across primarily the Downeast coast of Maine, some locally
higher totals are probable as reflected by pronounced spread in the
WSE plumes.

Additionally, in the wake of this clipper, increasing CAA
atop the Great Lakes, despite significant ice cover, will result in
periods of lake effect snow, primarily E/SE of Lake Ontario with
some lighter snowfall east of Lake Erie which is mostly ice
covered. WPC probabilities for this LES are high (>70%) for 4+
inches for the western Adirondacks, Tug Hill Plateau, Finger Lakes
region, and northern Chautauqua Ridge. The greatest accumulations,
which may exceed 8 inches (30% chance) are across the Tug Hill.


...Sierra Nevada to the Central/Southern Rockies...
Days 1-2...

A closed mid-level low positioned along the coast of northern CA
will generally fill in place as the accompanying longwave trough
elongates back to the southwest as secondary vorticity energy
rotates through the base ot approach southern CA and Baja by Friday
morning. This stalled evolution will result in a resurgence of an
upper level jet streak to sharpen downstream of this trough axis,
and while the secondary jet streak tonight into Thursday won't be
as powerful as the lead jet, it will maintain moisture advection
and broad LFQ diffluent ascent from CA into the Central Rockies.
The overlap of this jet streak with broad but persistent SW mid-
level flow also downstream of the primary trough axis will surge
moisture eastward as far as CO as reflected by NAEFS IVT
percentiles surging to above the 99th percentile in CO, with
prolonged anomalies above the 90th percentile back into the Great
Basin.

This plume of moisture will be primarily shed eastward within a WAA
plume, so snow levels will be generally 6000-7000 ft, lowering
slowly as the trough axis pivots eastward, but this will likely be
accompanied by rapid drying and a resulting cutoff of
precipitation. For this reason, the heaviest snowfall accumulations
are likely to be above 7000 ft (as high as 8000 ft in CO), with a
wane in precipitation expected as snow levels fall. WPC
probabilities D1 are high for at least 6 inches of snow in the high
Sierra, the Uintas/Wasatch, the Tetons/Wind Rivers, and parts of
the CO Rockies including the Park Range. D2 probabilities compress
and fall rapidly, leading to just residual elevated probabilities
above 30% for 4+ inches in the CO Rockies.


...Southern Rockies...
Day 3...

The same secondary shortwave responsible for elongating the trough
over CA/Great Basin D2 will shed eastward Friday morning, moving
across southern CA/Baja Norte before closing off once again near
the Four Corners Friday evening. This evolution will promote
downstream ascent through impressive height falls paired with
modest jet streak amplification, leading to widespread deep layer
lift spreading into the Four Corners and southern Rockies Friday
into Saturday. The antecedent thermal structure will be modest for
snowfall (snow levels 8000-9000 ft), but increasing ascent within
a moistening column will expand precipitation and allow for snow,
which could be heavy, especially in the higher terrain of the
Sangre de Cristos, White Mountains, and San Juans, with some
dynamic cooling of the column possible later D3 as some deformation
develops across northern NM. Still a lot of uncertainty in the
exact evolution, but at this time WPC probabilities indicate a
moderate to high risk (50-90% chance) for at least 4 inches in the
higher terrain.


The probability of significant icing across the CONUS is less than
10 percent.


Weiss


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 111850
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
150 PM EST Wed Feb 11 2026

Valid 00Z Thu Feb 12 2026 - 00Z Sun Feb 15 2026


...Eastern Great Lakes & Central Appalachians...
Day 1...

Strong clipper system has exited into the eastern Atlantic and set
up a CAA regime through tonight with modest northwesterly flow and
850 mb temperatures as low as -15C. This will lead to continued lake-enhanced/upslope snowfall into the favorable terrain from the
central Appalachians through the eastern Great Lakes and northern
New England ranges. However, this period of light to moderate snow
will be short-lived as high pressure builds in over the Mid-
Atlantic on Friday and the next weak clipper approaches New England
Friday night. WPC probabilities are low (<20%) for most regions
outside of the Laurel Highlands of southwest PA and areas downwind
of Lake Ontario.


...Sierra Nevada to the Central/Southern Rockies...
Days 1-2...

A closed mid-level low positioned along the coast of northern CA
will generally fill in place as the accompanying longwave trough
elongates back to the southwest as secondary vorticity energy
rotates through the base ot approach southern CA and Baja by Friday
morning. This stalled evolution will result in a resurgence of an
upper level jet streak to sharpen downstream of this trough axis,
and while the secondary jet streak tonight into Thursday won't be
as powerful as the lead jet, it will maintain moisture advection
and broad LFQ diffluent ascent from CA into the Central Rockies.
The overlap of this jet streak with broad but persistent SW mid-
level flow also downstream of the primary trough axis will surge
moisture eastward as far as CO as reflected by NAEFS IVT
percentiles surging to above the 99th percentile in CO, with
prolonged anomalies above the 90th percentile back into the Great
Basin.

This plume of moisture will be primarily shed eastward within a WAA
plume, so snow levels will be generally 6000-7000 ft, lowering
slowly as the trough axis pivots eastward, but this will likely be
accompanied by rapid drying and a resulting cutoff of
precipitation. For this reason, the heaviest snowfall accumulations
are likely to be above 7000 ft (as high as 8000 ft in CO), with a
wane in precipitation expected as snow levels fall. WPC
probabilities D1 are high for at least 6 inches of snow in the
Uintas/Wasatch, the Tetons/Wind Rivers, and parts of the CO Rockies
including the Park Range. D2 probabilities compress and fall
rapidly, leading to just residual elevated probabilities above 20%
for 4+ inches in the CO Rockies. Most probabilities drop off below
20% after 00z tonight in Sierra given a majority of the
precipitation occurs prior to 00z tonight.


...Southern Rockies...
Day 3...

The same secondary shortwave responsible for elongating the trough
over CA/Great Basin D2 will shed eastward Friday morning, moving
across southern CA/Baja Norte before closing off once again near
the Four Corners Friday evening. This evolution will promote
downstream ascent through impressive height falls paired with
modest jet streak amplification, leading to widespread deep layer
lift spreading into the Four Corners and southern Rockies Friday
into Saturday. The antecedent thermal structure will be modest for
snowfall (snow levels 8000-9000 ft), but increasing ascent within
a moistening column will expand precipitation and allow for snow,
which could be heavy, especially in the higher terrain of the
Sangre de Cristos, White Mountains, and San Juans, with some
dynamic cooling of the column possible later D3 as some deformation
develops across northern NM. Still a lot of uncertainty in the
exact evolution, but at this time WPC probabilities indicate a
moderate risk (40-70% chance) for at least 4 inches in the higher
terrain.


...Washington Cascades...
Day 3...

By late day 2 into day 3, the next upper trough to approach the
West Coast from the Gulf of Alaska orients a weak axis of IVT (<300
kg/m/s) into the Cascades. Snow levels start out rather low and are
forecast to drop below 2,000 ft and below pass level. However,
precipitation amounts appear light enough to avoid heavier snow
amounts. Still, WPC probabilities for at least 4 inches of snow are
high (>70%) in the Cascades above about 4,000 feet. Probabilities
for at least 4 inches of snow for Stevens and Snoqualmie passes
are between 20-40%.


The probability of significant icing across the CONUS is less than
10 percent.


Snell/Weiss


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 120819
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
319 AM EST Thu Feb 12 2026

Valid 12Z Thu Feb 12 2026 - 12Z Sun Feb 15 2026


...Central & Southern Rockies...
Days 1-2...

A broad upper-level trough west of Baja California is funneling
anomalous moisture into the Four Corners region today with modest
500-700mb Q-vector convergence over the central Rockies. The lack
of a continental polar (cP) airmass is keeping periods of snow
confined to elevations above 8,000ft in the Wasatch and CO Rockie
today and into Thursday night. A brief lull in the snowfall occurs
Thursday night, but heavier snowfall returns to the Central and
Southern Rockies on Friday as the aforementioned upper trough
moves east towards AZ. 700-500mb height falls, 500mb PVA, and PWs
above the 90th climatological percentile will support mountain
snow as far south as the Gila Mountains to as far east as the
Sangre De Cristo range. Similar to Thursday's snowfall, the lack of
a reasonably cold airmass will keep snow levels above 7,000ft,
with the heavier snowfall totals residing above 8,000ft. The
increased upper-level synoptic-scale forcing will improve snowfall
rates in the higher terrain compared to Thursday. 48-hour WPC
probabilities show low-to-moderate chances (40-60%) for snowfall
totals >4" in the Wasatch, the AZ Gila Mountains, and the CO/NM
Rockies, with the higher confidence in snowfall >4" being above
9,000ft. In the peaks of the CO Rockies and Gila Mountains, there
are some low chance probabilities (<30%) for snowfall totals >8"
through Saturday morning.

...Northern New York...
Days 2-3...

A progressive 500mb vorticity max over Ontario Friday afternoon
will provide sufficient upper-level ascent atop a low-level warm
front driven by a narrow sliver of 850mb WAA. Guidance is coming
into better agreement on a period of moderate snow, potentially
falling heavily at times, along the shores of Lake Ontario on east
into the Tug Hill and Adirondacks Friday night. Mean flow out of
the NW with residual 700-300mb moisture will support lingering
periods of snow into the Tug Hill and Adirondacks into Saturday
morning before tapering off by Saturday afternoon. Most snowfall is
likely to range between a coating-3" for much of northern New
York, although the Tug Hill and Adirondacks do show low chances
(<20%) for localized amounts >4" through Saturday morning.

...Washington Cascades & Northern Rockies...
Days 2-3...

An upper-level trough in the Gulf of Alaska will dive south just
off the coast of British Columbia and direct a plume of rich
Pacific moisture at the Pacific Northwest Friday afternoon and
through Saturday morning. A passing cold front and height falls in
advance of the encroaching upper trough will cause snow levels to
drop as low as 2,000ft in the Olympics and Cascades. Elevations in
the WA Cascades above 4,000ft sport the better chances for snowfall
amounts surpassing 6", while most elevations below 3,000ft range
between a coating-3". WPC probabilities for at least 4 inches of
snow for Stevens and Snoqualmie passes are between 30-50%. The
plume of Pacific moisture spills eastward into the Northern Rockies
with the Bitterroots, Sawtooth, and Lewis Ranges most likely to
receive measurable snowfall starting Friday evening and continuing
throughout the day Saturday. Similar to the Cascades, most snowfall
totals will be minor (coating-3"), although some localized totals

6" in the peaks of the Bitterroots and Lewis Range are possible.

The probability of significant icing across the CONUS is less than
10 percent.


Mullinax





$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 121815
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
115 PM EST Thu Feb 12 2026

Valid 00Z Fri Feb 13 2026 - 00Z Mon Feb 16 2026


...Central & Southern Rockies...
Days 1-2...

A broad upper-level trough lifting northeastward over Baja
California will continue to funnel anomalous moisture into the
southern Rockies region through Friday with modest 500-700mb
Q-vector convergence over the central Rockies. The lack of a
continental polar (cP) airmass is keeping periods of snow confined
to elevations above 8,000ft in the Wasatch and CO Rockies into
Thursday night. A brief lull in the snowfall occurs Thursday night,
but heavier snowfall returns to the Central and Southern Rockies
on Friday as the aforementioned upper trough moves east towards AZ.
700-500mb height falls, 500mb PVA, and PWs above the 90th
climatological percentile will support mountain snow as far south
as the Gila Mountains to as far east as the Sangre De Cristo range.
Similar to Thursday's snowfall, the lack of a reasonably cold
airmass will keep snow levels above 7,000ft, with the heavier
snowfall totals residing above 8,000ft. The increased upper-level synoptic-scale forcing will improve snowfall rates in the higher
terrain compared to Thursday. 48-hour WPC probabilities show low-
to-moderate chances (40-60%) for snowfall totals >4" in the
Wasatch, the AZ Gila Mountains, and the CO/NM Rockies, with the
higher confidence in snowfall >4" being above 9,000ft. In the peaks
of the CO Rockies and Gila Mountains, there are some low chance
probabilities (<30%) for snowfall totals >8" through Saturday.


...Northern New York...
Days 2-3...

A progressive 500mb vorticity max over Ontario Friday afternoon
will provide sufficient upper-level ascent atop a low-level warm
front driven by a narrow sliver of 850mb WAA. Guidance is coming
into better agreement on a period of moderate snow, potentially
falling heavily at times, along the shores of Lake Ontario on east
into the Tug Hill and Adirondacks Friday night. Mean flow out of
the NW with residual 700-300mb moisture will support lingering
periods of snow into the Tug Hill and Adirondacks into Saturday
morning before tapering off by Saturday afternoon. Most snowfall is
likely to range between a coating-3" for much of northern New
York, although the Tug Hill and Adirondacks do show low chances
(<20%) for localized amounts >4" through Saturday morning.


...Cascades & Northern Rockies...
Days 2-3...

An upper-level trough in the Gulf of Alaska will dive south just
off the coast of British Columbia and direct a plume of rich
Pacific moisture at the Pacific Northwest Friday afternoon and
through Saturday morning. A passing cold front and height falls in
advance of the encroaching upper trough will cause snow levels to
drop as low as 2,000ft in the Olympics and Cascades. Elevations in
the WA Cascades above 4,000ft sport the better chances for snowfall
amounts surpassing 6", while most elevations below 3,000ft range
between a coating-3". WPC probabilities for at least 4 inches of
snow for Stevens and Snoqualmie passes are between 30-60%. The
plume of Pacific moisture spills eastward into the Northern Rockies
with the Bitterroots, Sawtooth, and Lewis Ranges most likely to
receive measurable snowfall starting Friday evening and continuing
throughout the day Saturday. Similar to the Cascades, most snowfall
totals will be minor (coating-3"), although some localized totals

6" in the peaks of the Bitterroots and Lewis Range are possible.

Lastly, the passing cold front will sink southward over the OR
Cascades as snow levels remain around 4,000ft.


...California...
Day 3...

By the end of Day 3 (00z Mon), the upper trough approaching the
West Coast is forecast to deepen into an anomalous upper low (below
the 1st climatological percentile per the 00z NAEFS). In response,
subtropical moisture will begin to move inland across northern
California ahead of the cold front extending on the eastern
periphery of the upper level system. Snow levels are expected to
start around 5,000ft during this time frame. WPC probabilities
currently reach 40-60% for at least 8 inches of snowfall across the
Klamath Mts and Shasta Siskiyous. Much heavier snowfall is
forecast across the Sierra Nevada and the California ranges after
00z Mon, see WPC's extended range discussion for more information.



The probability of significant icing across the CONUS is less than
10 percent.


Snell/Mullinax




$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 130819
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
319 AM EST Fri Feb 13 2026

Valid 12Z Fri Feb 13 2026 - 12Z Mon Feb 16 2026


...Central & Southern Rockies...
Days 1-1.5...

A broad upper-level trough lifting northeastward over Baja
California will continue to funnel anomalous moisture into the
Four Corners region today with 500-700mb Q-vector convergence over
the central and southern Rockies. The lack of a continental polar
(cP) airmass is keeping periods of snow confined to elevations
above 8,000ft throughout the Four Corners' mountain ranges today
and into early Saturday morning. 700-500mb height falls, 500mb PVA,
and PWs above the 90th climatological percentile will support
mountain snow as far south as the Gila Mountains to as far east as
the Sangre De Cristo range. The increased upper-level synoptic-
scale forcing will improve snowfall rates in the higher terrain
with >1"/hr rates at times. 48-hour WPC probabilities show
modertae-to-high chances (50-80%) for snowfall totals >4" in the
AZ Gila Mountains and the CO/NM Rockies, with the higher
confidence in snowfall >6" being above 9,000ft. In the peaks of
the CO Rockies and Gila Mountains, there are some low chance
probabilities (<30%) for snowfall totals >8" through Saturday
morning.


...Northern New York...
Day 1...

A progressive 500mb vorticity max over Ontario Friday afternoon
will provide sufficient upper-level ascent atop a low-level warm
front driven by a narrow sliver of 850mb WAA. Guidance is coming
into better agreement on a period of moderate snow, potentially
falling heavily at times, along the shores of Lake Ontario on east
into the Tug Hill and Adirondacks Friday night. Mean flow out of
the NW with residual 700-300mb moisture will support lingering
periods of snow into the Tug Hill and Adirondacks into early
Saturday morning before tapering off by midday. Most snowfall is
likely to range between a coating-3" for much of northern New York,
although the Tug Hill features low chances (<20%) for localized
amounts >4" through Saturday morning.


...Cascades & Northern Rockies...
Days 1-3...

An upper-level trough in the Gulf of Alaska will dive south just
off the coast of British Columbia and direct a plume of rich
Pacific moisture at the Pacific Northwest this afternoon and
into Saturday. A passing cold front and height falls in advance of
the encroaching upper trough will cause snow levels to drop as low
as 2,000ft in the Olympics and Cascades. Elevations in the WA
Cascades above 4,000ft sport the better chances for snowfall
amounts surpassing 6", while most elevations below 3,000ft range
between a coating-3". WPC probabilities for at least 4 inches of
snow for Stevens and Snoqualmie passes are between 40-60%. The
plume of Pacific moisture spills eastward into the Northern Rockies
with the Bitterroots, Sawtooth, and Lewis Ranges most likely to
receive measurable snowfall starting Friday evening and continuing
throughout the day Saturday. The Northern Rockies will remain
downstream of a robust 250mb jet streak and steady 500mb PVA
advection through Sunday as well, keeping snow in the forecast
through the weekend's conclusion. Similar to the Cascades, most
snowfall totals will be minor (coating-3") at the lower elevations.
For the more remote elevations above 5,000ft in the Bitterroots and
Lewis Range, 2-hour WPC probabilities show moderate-to-high chances
(50-80%) for snowfall totals >8" with totals surpassing 12" above
6,000ft in the Lewis Range. Meanwhile, as the passing cold front
will sinks southward over the OR Cascades, snow levels will remain
around 4,000ft with most heavy snowfall staying in the more
remote/volcanic peaks.


...California...
Days 2.5-3...

A potent closed 500mb low west of CA will emanate healthy 500mb PVA
over the Golden State as early as Sunday afternoon with diffluent
flow at the nose of a strengthening 500mb jet streak. Increasing 850-300mb moisture ahead of the trough steadily increases over northern CA
with periods of mountain snow unfolding in the Siskiyou/Shasta. The
500mb low by Sunday night is a robust one, highlighted by 500mb
heights per ECMWF that are below the 1st climatological percentile.
Ahead of the upper low, a 500-750 kg/m/s IVT will direct
subtropical East Pacific moisture northward into the Sierra Nevada
by early Monday morning with snow levels down to 5,000ft. Sunday
night into early Monday morning marks the beginning of a multi-day
barrage of heavy mountain snow throughout much of the Golden State
with heavy snow eventually starting to accumulate during the day
Monday as far south as the Transverse and Peninsula Ranges down to
5,000ft. See WPC's extended range discussion for more information,
but it is worth noting WPC's WSSI-P shows moderate-to-high chances
(50-70%) for Major impacts in the central and southern Sierra
Nevada on Presidents' Day that then jump to >70% for all of the
Sierra Nevada above 6,000ft by Tuesday. Residents and those
traveling through passes in California next week should monitor
the forecast closely in the coming days.


...Central Appalachians & Mid-Atlantic...
Day 3...

...High confidence in a moisture-latent storm system, low
confidence in precipitation-type from the Appalachians to the I-95
corridor...

A sharp 500mb trough tracking through the Lower MS Valley early
Sunday morning will tap into ample Gulf moisture and direct it
northeast into the southern and central Appalachians. In addition,
a strong >140kt jet streak southeast of the MA Capes is placing its
diffluent right-entrance region over the Mid-Atlantic, providing
excellent upper-level divergence aloft. Guidance is in good
agreement on a rather strong surface low (sub 1000mb low) tracking
across northern MS/AL that, according to the ECMWF, is highly
anomalous, with the aforementioned pressure being below the 1st
climatological percentile. The integrated vapor transport (IVT)
over the Southeast tops 750 kg/m/s, exceeding the 97.5
climatological percentile, and results in moderate-to-heavy
precipitation moving into the Mid- Atlantic Sunday morning and
through Sunday evening.

While there is no shortage of moisture at this system's disposal,
the cold airmass in advance of the storm is quite marginal. Despite
the presence of high pressure over New England, the temperature
regime associated with this high pressure is not particularly cold
at all. Using a combination of GEFS/EPS percentiles, 10th
percentile temperatures in northern MD are 32-34F, with 50th
percentile values in the mid 30s. Meanwhile, dew points are likely
to range between the upper 20s and low 30s. The resulting wet-bulb
temperatures at the surface tend to hover around or slightly above
freezing in central Appalachians, northern VA, northern MD, and the
DelMarVa Peninsula. With temperatures in the surface-850mb layer
being isothermal along the 0C isotherm to even 1-2C above freezing,
the potential for snowfall will be heavily dependent upon
elevation and dynamic cooling via strong vertical velocities and
heavy precipitation rates. This system is very much more of a
March-like storm system, where mesoscale banding and elevation are
the primary methods for which accumulating snow would occur.

WPC probabilities are not overly impressed at this time with <30%
chances for over 1" of snowfall in the central Appalachians and
northern Mid-Atlantic. Given the lack of a thermally-supportive
boundary layer via marginal wet-bulb temperatures, it will prove
difficult to support a widespread snow event. However, as the event
encroaches upon the hi-res CAMs guidance window, confidence in
whether a narrow swath of measurable snow from the central
Appalachians to the Mid-Atlantic I-95 corridor will come into
better focus. For now, residents in the central Appalachians and
Mid-Atlantic should, at minimum, expect a dreary/wet Sunday with
the potential for some snow mixing in over elevated terrain.


The probability of significant icing across the CONUS is less than
10 percent.


Mullinax






$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 131929
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
229 PM EST Fri Feb 13 2026

Valid 00Z Sat Feb 14 2026 - 00Z Tue Feb 17 2026


...Central & Southern Rockies...
Day 1...

A sharp upper trough over AZ/northern Mexico this evening will
continue eastward tonight and reach West Texas tomorrow afternoon.
Moisture anomalies are high, but mostly in the warm sector.
However, the northern reaches of PW anomalies >97th percentile
overnight over the San Juans and Sangre de Cristos will support
mountain snow that will fall heavy at times through Saturday
morning. The progressive movement will limit accumulations, but SW
flow this evening will capitalize on upslope potential in the
terrain until the trough axis passes through. WPC probabilities for
at least 4 inches of snow are >50% above 10,000ft as snow levels
are rather high.


...Central/Western/Upstate New York...
Day 1...

A compact mid-level shortwave will move quickly out of Ontario and
through western/central NYS overnight, aiding in producing some
generally light snow across the region with the potential for some
locally moderate snow at times that will end on Saturday morning.
Most snowfall is likely to range between a coating-3" for much of
Upstate New York.


...Cascades & Northern Rockies...
Days 1-3...

Troughing west of the BC and the Pac NW will dig southward into an
upper low west of NorCal. This will send a modest cold front into
the Cascades and northern Rockies tonight/Saturday and linger
across the region as the flow remains generally from the southwest
aloft. Snow levels initially around 3500-4000ft will drop to around
2000-3000ft overnight into Saturday, bringing snow to many of the
passes. Moisture will continue eastward to the northern Rockies
(northern ID to northwestern MT) and the typical higher elevations
above 5000ft will see light to modest snowfall. Snow will end in
the Cascades during the day Saturday and diminish (though not truly
end) over the Rockies into Sunday as onshore flow continues in
some form. Another surge of moisture will bring light snow to the
Cascades by Monday with even lower snow levels to around 1000ft
(north) to 2000 ft (south) in the Cascades, but with light amounts.
For day 1, WPC probabilities for at least 4 inches of snow are

30% for Stevens and Snoqualmie passes. Into Monday night (late day

3), WPC probabilities for at least 2 inches of snow are >30% into
elevations as low as 2500-3000ft.


...California...
Days 2-3...

Southern extent of the anomalously deep troughing affecting the
Pacific Northwest (above) will result in a period of moderate to
locally heavy mountain snow for the Sierra Sunday into at least
Monday. A surface cold front, tied to an occluding low, will slowly
move onshore as a 120kt jet streak promotes heavier snowfall into
the Sierra Monday. Moisture will be modest (500-750 kg/m/s IVT and
PWs touching the 90th percentile) with the best moisture flux just
south of the region into AZ. Snow levels will generally range from
4500ft to 6000ft from north to south on Monday, then fall by the
end of this forecast period in northern areas to below 4000ft as
the trough approaches (and lower thereafter). Snow will continue
beyond this forecast period with major impacts to at least the high
Sierra per the WSSI-P probabilities (>50%) that increase into the
medium range (>80-90%). WPC probabilities for at least 18 inches of
snow are >50% above 6000-7000ft or so.


...Central Appalachians & Mid-Atlantic...
Days 2.5-3...

A southern system will likely slide eastward late Sun into Mon
with some light wintry precipitation on the northern side, but
trends are toward less QPF in a marginally conducive environment
and probabilities for even light snow are low.


The probability of significant icing across the CONUS is less than
10 percent.


Fracasso


$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 140832
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
332 AM EST Sat Feb 14 2026

Valid 12Z Sat Feb 14 2026 - 12Z Tue Feb 17 2026


...Cascades...
Days 1 & 3...

A broad upper-level troughing pattern off the Pacific NW coast
will continue to supply lingering low-mid level moisture that
allows for light snow through this morning. Snow levels will drop
to as low as 2000-3000ft today and into Saturday evening, bringing
snow to many of the passes over the WA Cascades. Following a lull
in snowfall Saturday night and into Sunday, another surge of
moisture will be supplied by a strengthening 500mb closed-low west
of British Columbia. Sharp height falls and excellent 500mb PVA
will be paired with an influx of 850-300mb mean-layer moisture to
produce periods of snow. Snow levels will plummet to as low as
800ft around the WA Cascades, while 2000 ft snow levels in the OR
Cascades will be more common. While these snow levels are getting
quite low, snowfall totals below 2,000ft in the WA/OR Cascades will
remain light. The heaviest snowfall will reside above 3,000ft
72-hour WPC probabilities show moderate chances (40-60%) for
snowfall totals >4" for both Snoqualmie Pass and Stevens Pass.
Given the long duration but lack of heavy hourly rates, WSSI-P
shows the chances for Minor Impacts are generally on the low side
(20-40%) with Monday having the best chances for some slick travel
conditions at pass level.


...California...
Days 2-3...

...Multiple days of heavy and disruptive snowfall to affect the
California mountain ranges beginning Sunday and continuing into
next week...

A pair of potent Pacific storm systems will work together to direct
copious amounts of moisture at the mountain ranges of the "Golden
State" starting Sunday. The first upper low west of California will
kickoff this multi-day heavy snow event on Sunday with snow falling
in the higher terrain of the Siskiyou, Shasta, and Salmon
Mountains. By Sunday night the upper low approaches, causing
heights to fall over CA and the strengthening IVT to direct
subtropical moisture at the state. Monday marks the beginning of
heavy snowfall along the Sierra Nevada with snow levels will
generally ranging from 4500ft to 6000ft from north to south
initially, then fall below 3000ft across northern CA as the other
potent Pacific trough approaches from the northwest. In both cases,
the state will be placed ahead of a pair of 500mb jet streaks that
will generate excellent upper-level divergence aloft, along with a
barrage of Pacific moisture and strong topographically-enhanced
snowfall rates. Heavy snowfall is expected as far south as the
Transverse Ranges above 6,000ft with WPC probabilities showing
moderate chances (40-60%) for snowfall totals >8" in the peaks of
the San Gabriel and San Bernadino Mountains.

California's mountain ranges welcome the snow, although it will
come down fast and furious on Monday and continue into Tuesday.
Through the end of this discussion's timeframe (12Z Tues), multiple
feet of snow will have fallen above 6,000ft along the Sierra
Nevada. WPC probabilities show high chances (>70%) for >24" of
snow having fallen along the I-80 pass by 12Z Tuesday and more snow
still to come. The WSSI-P depicts a highly impactful snow event
along the Sierra Nevada with high chances (>70%) for Major Impacts
above 6,00ft, including the I-80 pass. In fact, for the higher
elevations above 8,000ft, the WSSI-P shows moderate chances (>50%)
for Extreme Impacts, suggesting the potential for significant
impacts to infrastructure. Travel will be dangerous to impossible
in the Sierra Nevada into Tuesday. Note that there are also high
chances (>70%) for Minor Impacts for I-5 around Mount Shasta,
signifying potential travel delays for I-5 in the more elevated
terrain of northern CA.


...Intermountain West...
Days 1-3...

Pacific moisture ahead of the longwave upper trough off the West
Coast will spill over the Cascades and Sierra Nevada and reach many
ranges across the Intermountain West this weekend and into early
next week. With a lack of a frigid airmass ahead of this healthy
moisture source, snow will largely be confined to many of the
taller mountain peaks that sorely need beneficial snowpack. The
heaviest snowfall will reside in the Bitterroots, the Lewis Range,
Sawtooth, and the Blue Mountains whee 72-hour WPC probabilities
show moderate-to-high chances (50-80%) for snowfall totals >8".
Localized amounts ranging between 12-24" are most likely to occur
along the remote reaches of the Lewis Range and peaks of the Blue
Mountains. Farther south, most accumulations in the Great Basin,
the Wasatch, Uinta, Mogollon Rim, and CO/NM Rockies will be on the
lighter side. The peaks around Zion Nat'l Park on north along the
Wasatch sport moderate-to-high chances (50-70%) for snowfall totals

4". Otherwise, most mountain ranges are likely to see 1-4" of

snowfall, with additional snowfall still to come on Tuesday.


...Northeast...
Day 2...

The last 24 hours have seen some model guidance (GFS/ECMWF)
gradually creep north with the precipitation shield. This is due to
the approaching 500mb shortwave over western PA coming in
stronger, thus leading to healthier PVA aloft and more 250mb jet
streak enhancement aloft. While boundary layer temperatures along
I-95 south of Philadelphia remain quite marginal on Sunday,
elevated terrain north and west of the Delaware River are likely to
have better chances to see wet snow Sunday afternoon. As the upper
trough in the Carolinas spawns low pressure over the NC Outer
Banks Sunday evening, 850-700mb WAA to the north of the low will
support narrow banding of snow from eastern PA and northern NJ to
the NYC metro, Long Island, and coastal southern New England. There
remains notable spread in model guidance in the position of this
band, but trends in not only the GFS/ECMWF guidance but also their
AI counterparts are showing additional support for a ribbon of
light snow. WPC probabilities show low-to-moderate chances (30-50%)
for snowfall totals >1" from the Delaware and Lehigh Valleys on
east to Long Island, but probabilities for >2" of snowfall are
<20%, showing that most totals are minor and likely to range
between a coating-2". There is the potential for additional
changes to this forecast in the next 12-24 hours.


The probability of significant icing across the CONUS is less than
10 percent.


Mullinax





$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 141922
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
222 PM EST Sat Feb 14 2026

Valid 00Z Sun Feb 15 2026 - 00Z Wed Feb 18 2026


...Cascades...
Days 1 & 3...

A shearing apart weak trough across Washington State will provide
weak forcing for light snow for many of the passes over the
Cascades. Meanwhile, snow levels will drop to as low as
1,000-2,000ft through Sunday. For the most part, there will be a
lull in snowfall tonight and into Sunday. On Monday, another surge
of moisture will be supplied by a second strengthening 500mb
closed-low west of British Columbia, which will dive parallel to
the coast through Tuesday. Sharp height falls and excellent 500mb
PVA will be paired with an influx of 850-300mb mean-layer moisture
to produce periods of snow. Snow levels will plummet to as low as
800ft around the WA Cascades, while 2000 ft snow levels in the OR
Cascades will be more common. While these snow levels are getting
quite low, snowfall totals below 2,000ft in the WA/OR Cascades will
remain light. The heaviest snowfall will reside above 3,000ft
where 72-hour WPC probabilities remain in the moderate range
(40-60%) for snowfall totals >4" for both Snoqualmie Pass and
Stevens Pass. Given the long duration but lack of heavy hourly
rates, WSSI-P shows the chances for Minor Impacts are generally on
the low side (20-40%) with Monday having the best chances for some
slick travel conditions at pass level.


...California...
Days 2-3...

...Multiple days of heavy and disruptive snowfall to affect the
California mountain ranges beginning Sunday and continuing into
next week...

A pair of potent Pacific storm systems will work together to direct
copious amounts of moisture at the mountain ranges of the "Golden
State" starting Sunday. A broad positively-tilted upper-level troughing
pattern off the Pacific NW coast will supply low-mid level
moisture that allows for light snow through tonight into the
higher terrain of the Siskiyou, Shasta, and Salmon Mountains. Snow
levels will gradually drop below 5,000 ft into these ranges, where
1-2 feet of new snow accumulation are possible at the higher
elevations through the day Sunday.

By Sunday night the upper low approaches, causing heights to fall
over CA and the strengthening IVT to direct subtropical moisture at
the state. Monday marks the beginning of heavy snowfall along the
Sierra Nevada with snow levels will generally ranging from 4,500ft
to 6,000ft from north to south initially, then fall below 3,000ft
across northern CA as the other potent Pacific trough approaches
from the northwest. In both cases, the state will be placed ahead
of a pair of 500mb jet streaks that will generate excellent upper-
level divergence aloft, along with a barrage of Pacific moisture
and strong topographically-enhanced snowfall rates. Heavy snowfall
is expected as far south as the Transverse Ranges above 6,000ft
with WPC probabilities showing low to moderate chances (30-50%) for
snowfall totals >8" in the peaks of the San Gabriel and San
Bernadino Mountains.

California's mountain ranges welcome the snow, although it will
come down fast and furious on Monday and continue into Tuesday.
Through the end of this discussion's timeframe (00Z Wed), multiple
feet of snow will have fallen above 6,000ft along the Sierra
Nevada. WPC probabilities show high chances (>70%) for >24" of snow
having fallen along the I-80 pass by 12Z Tuesday and more snow
still to come. The WSSI-P depicts a highly impactful snow event
along the Sierra Nevada with high chances (>70%) for Major Impacts
above 6,000ft, including the Donner Pass. In fact, for the higher
elevations above 8,000ft from Lake Tahoe south, the WSSI-P shows
high chances (>70%) for Extreme Impacts, suggesting the potential
for significant impacts to infrastructure. Travel will be dangerous
to impossible in the Sierra Nevada into Tuesday. Note that there
are also high chances (>70%) for Minor Impacts for I-5 around Mount
Shasta, signifying potential travel delays for I-5 in the more
elevated terrain of northern CA.

By Tuesday, another round of heavy snow is expected into all of the
ranges of central and northern California as a strong upper level
low dives south along the coast, locally enhancing onshore flow and
moisture levels on the leading (southern) edge of the low. Snow
levels will fall to around 2,000 ft in far northern California to
below 5,000 ft into the Transverse Ranges. Storm total snow amounts
will approach 3 feet into the Shasta and Siskiyou ranges, over 4
feet across much of the Sierra Nevada, and amounts over a foot even
into the highest elevations of the Transverse Ranges.


...Intermountain West...
Days 1-3...

Pacific moisture ahead of the longwave upper trough off the West
Coast will spill over the Cascades and Sierra Nevada and reach many
ranges across the Intermountain West this weekend and into early
next week. With a lack of a frigid airmass ahead of this healthy
moisture source, snow will largely be confined to many of the
taller mountain peaks that sorely need beneficial snowpack. The
heaviest snowfall will reside in the Bitterroots, the Lewis Range,
Sawtooth, and the Blue Mountains where 72-hour WPC probabilities
show moderate-to-high chances (50-80%) for snowfall totals >8".
Localized amounts ranging between 12-24" are most likely to occur
along the remote reaches of the Lewis Range and peaks of the Blue
Mountains. Farther south, most accumulations in the Great Basin,
the Wasatch, Uinta, Mogollon Rim, and CO/NM Rockies will be on the
lighter side. The peaks around Zion Nat'l Park on north along the
Wasatch sport moderate-to-high chances (50-70%) for snowfall totals

4". Otherwise, most mountain ranges are likely to see 1-4" of

snowfall through Monday.

On Tuesday, a "bowling ball" low tracking south down the coast will
help guide upper level energy sweeping across the Southwest towards
the northern Plains. The energy between these two features will
lead to cyclogenesis across the northwestern Plains (northern
Wyoming and southeast Montana). The low and the upper wave over the
Southwest will cause widespread heavy snow at the higher elevations
of many of the mountains from Utah and Colorado north. 24-hour snow
totals are likely to exceed 6 inches from southern Utah and
southwest Colorado up through the Lewis Range in northwestern
Montana. While lower elevations will be either snow-free or only
pick up an inch or two, the mountains will likely upslope much
higher snow totals. WSSI-P values are high (>70%) for over 8
inches of snow into all of those ranges.

...Northeast...
Day 2...

The beginning of phasing of two separate 500 mb troughs will drive
the potential for a period of light snow across portions of the
Mid-Atlantic Sunday night. A southern stream disturbance over the
Southeast Sunday evening will transfer its energy to an equally
fast-moving disturbance in the northern stream over eastern Ohio.
With the northern disturbance intensifying, this will lead to
healthier PVA aloft and more 250mb jet streak enhancement aloft.
While boundary layer temperatures along I-95 south of Philadelphia
remain quite marginal on Sunday, a corridor from west of
Philadelphia through the city and east to NYC and Long Island look
to have the best potential for light snow Sunday night. The
weakening trough in the Carolinas spawns low pressure over the NC
Outer Banks Sunday evening, allowing 850-700mb WAA to the north of
the low to support narrow banding of snow from eastern PA and
northern NJ to the NYC metro, Long Island, and coastal southern New
England. There remains notable spread in model guidance in the
position of this band, but trends in not only the GFS/ECMWF
guidance but also their AI counterparts are showing additional
support for a ribbon of light snow. WPC probabilities show low-to-
moderate chances (30-50%) for snowfall totals >1" from the Delaware
and Lehigh Valleys on east to Long Island, but probabilities for

2" of snowfall are <20%, showing that most totals are minor and

likely to range between a coating-2".

The probability of significant icing across the CONUS is less than
10 percent.


Wegman/Mullinax








$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)

FOUS11 KWBC 150732
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
232 AM EST Sun Feb 15 2026

Valid 12Z Sun Feb 15 2026 - 12Z Wed Feb 18 2026


...Cascades & Olympics...
Days 2-3...

On Monday, a strengthening 500mb closed-low west of British
Columbia will slide south and just off the coast through Tuesday.
Sharp height falls and excellent 500mb PVA, combined with an
influx of 850-300mb mean-layer moisture and upslope enhancement,
will produce periods of snow over the Olympics and Cascades. Snow
levels will plummet to as low as 800ft around the WA Cascades and
Olympics, while 2000ft snow levels in the OR Cascades will be more
common. In fact, some of OR's coastal range could see snow to
elevations as low as 1,000ft. While these snow levels are getting
quite low, snowfall totals below 2,000ft in the WA/OR Cascades will
remain light. The heaviest snowfall will reside above 3,000ft
where 72-hour WPC probabilities remain in the moderate range
(40-60%) for additional snowfall totals >4" for both Snoqualmie
Pass and Stevens Pass. Given the long duration but lack of heavy
hourly rates, WSSI-P shows the chances for Minor Impacts are
generally on the low side (20-40%). Impacts are most likely to be a
combination of snow covered roads and reduced visibilities.


...California...
Days 2-3...

...Multiple days of heavy and disruptive snowfall to affect the
California mountain ranges beginning Sunday and continuing into
next week...

A pair of potent Pacific storm systems will work together to direct
copious amounts of moisture at the mountain ranges of the "Golden
State" beginning today and lasting into the middle of the upcoming
week. A broad positively-tilted upper level troughing pattern off
the Pacific NW coast will supply low-mid level moisture that
allows for light snow through tonight into the higher terrain of
the Siskiyou, Shasta, and Salmon Mountains. The heaviest snowfall
through Sunday are likely to reside above 5,000ft where 1-2 feet of
new snow accumulation are possible at the higher elevations
through Sunday night.

By Sunday night, the upper low approaches, causing mid-to-upper
level heights to fall over CA and the strengthening IVT to direct
subtropical moisture at the state. The state will be placed ahead
of a 500mb jet streak that will generate excellent upper- level
divergence aloft, along with a barrage of Pacific moisture and
strong topographically-enhanced snowfall rates. Monday marks the
beginning of heavy snowfall along the Sierra Nevada with snow
levels initially starting out around 6,000ft from north to south
initially, then falling to as low as 3,000ft by Monday night.
Farther north, snow level will dip below 3,000ft across northern CA
as the other potent Pacific trough approaches from the northwest.
Snowfall rates between 1-2"/hr will be common with some instances
of >3"/hr snowfall rates in the central and southern Sierra
Nevada. Heavy snow is also expected in the Transverse Ranges above
6,000ft.

By Tuesday, another round of heavy snow is expected across just
about all of the CA mountain ranges as a second, strong upper
level low dives south along the West Coast, enhancing onshore flow
and supplying additional moisture on the southern and eastern
flanks of the upper low. Snow levels will fall to around 1,000 ft
in far northern California (including the northern coastal range),
around 2,500ft in the Sierra Nevada, and just below 5,000 ft into
the Transverse Ranges with snow continuing to fall across the
state's mountain ranges into Wednesday.

California's mountain ranges welcome the snow, although it will
come down fast and furious both Monday and Tuesday. Through the
end of this discussion's timeframe (12Z Wed), multiple feet of
snow will have fallen above 5,000ft along the Sierra Nevada. WPC
probabilities show high chances (>70%) for >30" of snow having
fallen along the I-80 pass by 12Z Wednesday and more snow still to
come. The WSSI shows a large swath of Extreme Impacts (Substantial
disruptions to daily life; extremely dangerous travel or impossible
driving conditions, extensive closures) for elevations generally
above 6,000ft, although some Extreme impacts as low as 5,000ft are
possible. Major to locally Extreme impacts are showing up in the
peaks of the San Gabriel and San Bernadino mountains, with mostly Moderate-to-Major Impacts (increasingly more disruptive to travel
jumping from Moderate to Major). Note that there are also Minor to
locally Moderate Impacts along I-5 around Mount Shasta, signifying
potential travel delays for I-5 in the more elevated terrain of
northern CA.


...Intermountain West...
Days 1-3...

Pacific moisture ahead of the longwave upper trough off the West
Coast will spill over the Cascades and Sierra Nevada and reach many
ranges across the Intermountain West today and into the upcoming
week. With a lack of a frigid airmass ahead of this healthy
moisture source, snow will largely be confined to many of the
taller mountain peaks that sorely need beneficial snowpack. The
heaviest snowfall will reside in the Bitterroots, the Lewis Range,
Sawtooth, and the Blue Mountains where Farther south, most
accumulations in the Great Basin, the Wasatch, Uinta, Mogollon Rim,
and CO/NM Rockies will be on the lighter side. The peaks around
Zion Nat'l Park on north along the Wasatch sport moderate-to-high
chances (50-70%) for snowfall totals >4". Otherwise, most mountain
ranges are likely to see 1-4" of snowfall through Monday.

On Tuesday, the highly anomalous upper-low off the Pacific NW coast
will help to usher the initial upper low over southern CA east into
the Intermountain West, causing widespread height falls and a
larger footprint of Pacific moisture to track through the Rockies.
Snow levels will lower to the valley floors in western Mt and
northern ID, with some light snow possible even in the Salt Lake
City area. Still, the lack of a frigid airmass at the surface will
keep the bulk of the heavy snow in the mountains with ranges such
as the Wasatch, Bear River, Tetons, Uinta, and Wind River seeing
locally heavy snowfall along their peaks. Many of the CO ROckies
will also receive snowfall, but the heavier amounts >8" will be
confined to elevations above 9,000ft.

72-hour WPC probabilities show high chances (>70%) for snowfall
totals >8" for most of the Intermountain West's ranges, but the
locally heavier total's (>12") are most likely to occur in the
peaks of the Lewis Range, the Bitterroots, Sawtooth, Blue, Bear
River, Wasatch, and Uinta.


...Upper Midwest & Great Lakes...
Day 3...

By 12Z Tuesday, the remnant yet vigorous trough that was originally
over southern CA late Monday will race across the Rockies and
project excellent 500mb PVA over the northern High Plains. The
ECMWF SATs shows a roaring 150kt 200mb jet streak (wind speeds
topping the 99.5 climatological percentile) over the Southwest will
place its divergent left-exit region over the Great Plains. With
the aid of lee-side downsloping and low-level WAA across the
Plains, an exceptionally deep surface low will form over southern
MT that reaches as low as 980mb Tuesday morning, or MSLP values
that are below the 1st climatological percentile. As WAA ahead of
the warm front reaches across the Upper Midwest, strong isentropic
ascent will ensue as the warm/moist air runs into a colder/drier
air-mass over northern ND and northern MN. Precipitation initially
starting as rain Tuesday afternoon will changeover to snow over
northeast MT, northern ND, and as far east as the MN Arrowhead
Tuesday night. Meanwhile, from northern MN and northern WI to the
northern tier of Michigan's Mitten, the overrunning setup would
favor a wintry mix of sleet and freezing rain Tuesday night and
into Wednesday morning. WPC probabilities show low chances (10-30%)
for pockets of over one-tenth of an inch of ice accretion in parts
of northern WI and MI.

There remains a high degree of uncertainty in the storm track, as
well as when the transition to snow would occur. Snow beneath the
strengthening TROWAL over northeast MT and northern ND would
perhaps not only support heavy snow, but the impressive strength of
the cyclone itself would foster blowing snow on its northern and
western flanks.In terms of snowfall, the MN Arrowhead sports low-
to-moderate chances (30-50%) for >4" of snowfall through 12Z Wed.
Most of far northeast MT, northern ND, and northern MN have
moderate chances (40-60%) for >2" of snowfall, but this is an area
where any minor change in duration or placement in the deformation
axis could result in notable changes to the snowfall forecast.
Regardless, the pressure gradient will be tight enough to where all
of these areas have moderate chances (40-60%) for Minor Impacts
(per WSSI-P) due to some combination of snowfall amounts of blowing
snow through early Wednesday morning.


...Northeast...
Day 1...

The airmass in the northern Mid-Atlantic and latest guidance
continues to favor areas farther north from southeast PA across
the Delaware River and into NJ and as far east as Long Island for
light snowfall. WPC probabilities show low-to moderate chances
(30-50%) for snowfall totals >1" from the Delaware and Lehigh
Valleys on east to Long Island, but probabilities for >2" of
snowfall are <30%, indicating that most totals are minor and
likely to range between a coating-2" from southeast PA (with
elevation) on east through northern NJ and across the NYC metro.
Snow should peak in intensity Sunday night and conclude by Monday
morning.


Mullinax





$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/105)