• MESO: Mesoscale Discussion 0755

    From COD Weather Processor@1:2320/107 to wx-storm@lists.illinois.edu on Sun May 17 20:39:16 2026
    ACUS11 KWNS 172039
    SWOMCD
    SPC MCD 172038=20
    OKZ000-KSZ000-TXZ000-172245-

    Mesoscale Discussion 0755
    NWS Storm Prediction Center Norman OK
    0338 PM CDT Sun May 17 2026

    Areas affected...portions of the central Great Plains

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

    Valid 172038Z - 172245Z

    Probability of Watch Issuance...40 percent

    SUMMARY...Isolated thunderstorm development is possible across the
    eastern Texas Panhandle, northwest Oklahoma, and south-central
    Kansas along a dryline this evening, with a conditional threat for
    all severe hazards. Trends are being monitored for possible watch
    issuance.

    DISCUSSION...Latest surface analysis depicts a surface low near the Kansas/Nebraska border with a trailing dryline extending
    south-southwestward through central Kansas into northwest Oklahoma
    and the Texas Panhandle, with recent visible satellite imagery
    depicting sporadic Cu developing along this boundary. East of the
    dryline, steep mid-level lapse rates (8.5+ C/km) and rich low-level
    moisture (as sampled by the 18z OUN/DDC observed soundings) are
    supporting strong instability, with 2500-3500+ J/kg MLCAPE analyzed
    via latest mesoanalysis.=20

    Notable uncertainty remains regarding the development of sustained thunderstorms owing to strong capping sampled by the 18z OUN
    sounding and nebulous upper-level forcing. While effective shear is
    forecast to remain modest (generally 25-35 kts), a conditional
    severe threat exists should a storm develop. The aforementioned
    steep mid-level lapse rates and modest effective shear would support
    a threat for large hail, with a strengthening southerly low-level
    jet also promoting an increasing tornado threat this evening with
    any developing/persistent supercells. Some high-res guidance also
    suggests some potential for the development of a linear segment,
    which would favor a greater risk for severe/damaging wind gusts.

    Trends will continue to be monitored, and watch issuance could be
    needed should convective initiation appear likely/imminent given
    this conditional severe threat.

    ..Chalmers/Mosier.. 05/17/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5FqUmtS0IEU0k7qtGlR1f8KaEZ2d2j-042WxaG1-p4vATDbdS7pj4X670Rs89ntOHKE0ibRTO= fKf3ZaswDmx7agXaWs$ for graphic product...

    ATTN...WFO...ICT...OUN...DDC...AMA...

    LAT...LON 35550050 36979991 38119945 38459914 38499853 38209813
    37459785 36749802 36229829 35609888 34909979 34790007
    34770041 34910059 35230062 35550050=20

    MOST PROBABLE PEAK TORNADO INTENSITY...100-125 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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    * Origin: Capitol City Online (1:2320/107)