• MESO: Mesoscale Discussion 1553

    From COD Weather Processor @1:2320/107 to All on Thu Jul 9 03:09:18 2026
    ACUS11 KWNS 090308
    SWOMCD
    SPC MCD 090308
    IAZ000-MOZ000-NEZ000-KSZ000-090515-

    Mesoscale Discussion 1553
    NWS Storm Prediction Center Norman OK
    1008 PM CDT Wed Jul 08 2026

    Areas affected...Southeast Nebraska...southwest Iowa...and northeast
    Kansas

    Concerning...Severe Thunderstorm Watch 473...

    Valid 090308Z - 090515Z

    The severe weather threat for Severe Thunderstorm Watch 473
    continues.

    SUMMARY...Scattered thunderstorms will likely continue into the
    overnight hours across portions of southeast Nebraska and into
    northeast Kansas. Isolated large hail and severe winds will be
    possible, but this threat should be sufficiently limited to preclude
    downstream watch issuance.

    DISCUSSION...An organized convective band with an evident book-end
    vortex continues to migrate eastward across the Missouri River into
    western IA. Although only sub-severe winds were observed with this
    line as it impacted Omaha, NE, KOAX velocity imagery continues to
    show pockets of strong/severe winds within the line. However, this
    band is beginning to exit the buoyancy gradient and will begin
    encountering a more stable air mass as it migrates further into IA.
    This should promote steady weakening over the next hour or so.

    Further southwest, new updrafts are noted developing just behind an
    outflow boundary surging south towards the KS/NE border. Although
    the downstream environment is conditionally favorable for organized
    convection (MLCAPE remains near 1500 J/kg with around 40 knots of
    effective bulk shear), it appears that convection will continue to
    be displaced behind the leading edge of the outflow, which will
    likely promote additional southward acceleration as the cold pool is convectively reinforced.

    Nonetheless, a few stronger convective cores may emerge given
    remaining MUCAPE downstream (based on the 00 UTC TOP RAOB) and
    recent MRMS VIL trends. This could pose a threat for sporadic large
    hail and isolated bursts of severe winds into northeast KS. This
    scenario appears to be supported by recent HRRR/RRFS time-lagged
    ensemble guidance which depicts a weak, but non-zero, signal for
    strong updraft helicity and severe winds. Given the limited
    confidence in a more widespread/robust severe threat, downstream
    watch issuance is currently not expected.

    ..Moore.. 07/09/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fjg!9qAnRDQqkp7yuTJEXNPsjvwEvue3CTNKsFelJFAp04h8rCwSq9ZVyIIrSls01goCk5w2-2pmncCb0teE32xQmZ9DHlc$ for graphic product...

    ATTN...WFO...DMX...EAX...OAX...TOP...ICT...GID...

    LAT...LON 39849878 40129895 40329891 40529862 40579811 40659769
    40879663 41139607 41439584 41689563 41819547 41809516
    41679485 41469461 41179453 40729486 40289516 39199591
    38949622 38769672 38749721 38839761 38979793 39849878

    MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
    MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


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    --- scorpsmtpd
    * Origin: Capitol City Online (1:2320/107)