ACUS11 KWNS 181650
SWOMCD
SPC MCD 181650
NJZ000-PAZ000-DEZ000-MDZ000-DCZ000-VAZ000-WVZ000-181815-

Mesoscale Discussion 1648
NWS Storm Prediction Center Norman OK
1150 AM CDT Sat Jul 18 2026

Areas affected...portions of southern Pennsylvania...eastern West Virginia...northern Virginia...much of
Maryland...Delaware...southern New Jersey

Concerning...Severe potential...Watch likely

Valid 181650Z - 181815Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorms are expected to increase in coverage and
intensity through early-mid afternoon. Damaging winds will be the
primary concern as storms evolve into eastward-moving clusters and
line segments. A watch is likely prior to 18z.

DISCUSSION...Strong boundary-layer heating of a very moist air mass
is ongoing across the discussion area as of 1645z, contributing to moderate/pockets of strong surface-based instability. Thunderstorms
will continue to increase in coverage across the higher terrain, and
along a north-south confluence zone across southern PA south into
northern VA, during the next few hours. As coverage continues to
increase and low-level lapse rates steepen, the potential for
damaging gusts will increase across the discussion area this
afternoon and early evening. Additionally, low-level shear will
remain locally enhanced in the vicinity of a warm front across
southeast PA/southern NJ. Deep-layer shear will be supportive of
supercell structures, and the risk for tornadoes, potentially
strong, will be maximized in this area.

Convective trends will continue to be monitored, and a watch is
likely prior to 18z.

..Bunting/Thompson.. 07/18/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fjg!_3CRVabObXnNRe72f6vDrQMpqB64hOqso1uItRscCtq4Cvu62Jn7xJAtzvnzxfVdVwycLIrWeJah53faEcZdskwpDJs$ for graphic product...

ATTN...WFO...PHI...AKQ...CTP...LWX...PBZ...

LAT...LON 39077931 40007859 40547698 40477526 40267451 39987411
39137439 38627538 38437699 38487839 38647934 39077931

MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


= = =
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.
--- scorpsmtpd
* Origin: capitolcityonline.net * KY, USA (1:2320/107)