• MESO: Mesoscale Discussion 1738

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Sun Jul 20 19:42:11 2025
    ACUS11 KWNS 201942
    SWOMCD
    SPC MCD 201941=20
    NEZ000-SDZ000-KSZ000-COZ000-202215-

    Mesoscale Discussion 1738
    NWS Storm Prediction Center Norman OK
    0241 PM CDT Sun Jul 20 2025

    Areas affected...south-central South Dakota across western Nebraska
    and toward northwest Kansas

    Concerning...Severe potential...Watch possible=20

    Valid 201941Z - 202215Z

    Probability of Watch Issuance...60 percent

    SUMMARY...Scattered severe storms appear likely later this afternoon
    from south-central SD across west-central NE and toward northwest
    KS. A few cells may produce large hail, with locally damaging gusts.
    A tornado is possible over southern SD into far northern NE after
    23Z. A portion of the area may require a watch.

    DISCUSSION...Surface map shows low pressure extending from southwest
    SD across western NE and into the CO/KS border area, with strong
    heating. This trough will continue to deepen, and sufficient
    convergence within the uncapped air mass should allow for widely
    scattered storms to develop late this afternoon.

    Of particular note is the warm front area which currently curls
    northwestward out of northern NE and into south-central SD. Here,
    heating is occurring on the cool side of the boundary, where
    dewpoints remain above 70 F and low-level shear is enhanced. Any
    supercell that develops here, most likely after 23Z, could be
    tornadic at times, and produce very large hail as it proceeds
    southeastward, aided by a modest evening low-level jet.

    Farther south into the deeper/heated air mass, higher based storms
    are expected, and overall shear is weaker as well. However, steep
    lapse rates will favor locally severe gusts, and even some hail in
    the early and robust formation stages.

    ..Jewell/Smith.. 07/20/2025

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8r1RHwilX2lUedIwbW9B0hLuecm4oJ63tRnZ2qhWszyXFHbKdKaQqYI2brvu2a1at_0e_87ES= 1BAX4CHchRp6nS3pGo$ for graphic product...

    ATTN...WFO...ABR...LBF...UNR...GLD...BOU...

    LAT...LON 42940011 41680031 40480068 39280162 39210233 40430230
    41640217 42900209 43440215 43740228 44020246 44250227
    44360152 44250113 43880051 42940011=20

    MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
    MOST PROBABLE PEAK WIND GUST...65-80 MPH
    MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


    =3D =3D =3D
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