• MESO: Mesoscale Discussion 0923

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Wed May 21 18:57:56 2025
    ACUS11 KWNS 211856
    SWOMCD
    SPC MCD 211855=20
    KSZ000-NEZ000-212130-

    Mesoscale Discussion 0923
    NWS Storm Prediction Center Norman OK
    0155 PM CDT Wed May 21 2025

    Areas affected...parts of south central Nebraska into north central
    Kansas

    Concerning...Severe potential...Watch unlikely=20

    Valid 211855Z - 212130Z

    Probability of Watch Issuance...20 percent

    SUMMARY...A consolidating area of southeastward developing
    thunderstorm activity may be accompanied by increasing strong to
    severe wind gusts by 4-6 PM CDT. It is not clear that a severe
    weather watch is needed, but trends will be monitored.

    DISCUSSION...Beneath seasonably cold (temperatures around/below -20
    C at 500 mb) and strong (40-50 kt at 500 mb) west-northwesterly
    mid-level flow, low-level lapse rates are becoming quite steep, with
    sufficient boundary-layer moisture to support weak CAPE and
    scattered developing thunderstorm activity across parts of south
    central Nebraska and northeastern Colorado into northwestern Kansas.
    It appears that convection will continue to gradually increase and
    modestly intensify with further destabilization through late
    afternoon.=20=20

    Aided by large-scale forcing for ascent associated with a
    southeastward developing area of lower/mid-tropospheric warm
    advection, various model output suggests that convection may
    gradually grow upscale into a cluster across the central
    Nebraska/Kansas border vicinity through 21-23Z. Coinciding with
    peak daytime heating, and deep boundary-layer mixing (including
    surface temperature/dew point spreads around 35-40F), strong
    downdrafts, enhanced by evaporative cooling and downward mixing of
    momentum, may contribute to a few locally severe surface gusts.=20
    Gradually, consolidating outflow may yield an expanding area of
    strong to, perhaps, severe gusts, before convection wanes this
    evening.

    ..Kerr/Guyer.. 05/21/2025

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8_szSnBv8vMztwMwHFSQDPcTXRyonEmIX-0guLtpovUOW6y6_T7q67T4a9-7faqOoRqgiIDWE= DYIWHT6NNRaTYUGqN0$ for graphic product...

    ATTN...WFO...OAX...TOP...ICT...GID...LBF...DDC...GLD...

    LAT...LON 40449751 39809697 38949798 38809924 40110119 41009922
    40449751=20

    MOST PROBABLE PEAK WIND GUST...55-70 MPH


    =3D =3D =3D
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