• MESO: Mesoscale Discussion 0497

    From COD Weather Processor@1:2320/107 to wx-storm@lists.illinois.edu on Wed Apr 22 19:51:57 2026
    ACUS11 KWNS 221951
    SWOMCD
    SPC MCD 221951=20
    NEZ000-OKZ000-KSZ000-SDZ000-TXZ000-COZ000-222145-

    Mesoscale Discussion 0497
    NWS Storm Prediction Center Norman OK
    0251 PM CDT Wed Apr 22 2026

    Areas affected...parts of the central and southern High Plains.

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

    Valid 221951Z - 222145Z

    Probability of Watch Issuance...20 percent

    SUMMARY...Isolated high-based thunderstorms are expected this
    afternoon and into the evening. Isolated severe wind gusts, and some
    hail are possible. Limited moisture and storm organization should
    preclude the need for a watch.

    DISCUSSION...As of 1945 UTC, visible imagery and radar analysis
    showed incipient thunderstorms developing along a weak
    dryline/surface pressure trough from parts of the central Plains
    (NE,SD, CO, into western KS and the southern High Plains). Strong
    diurnal heating of a modestly moist air mass, along with weak ascent
    from increasing southwesterly flow aloft transecting the Rockies has destabilized the air mass east of the boundary. Continued heating
    and ascent should support additional storm development this
    afternoon. Steep lapse rates (8-9 C km) and 30-40 kt of mid-level
    flow will support occasional stronger/organized updrafts with
    multicells or transient supercells.

    High LCLs around 3 km, owing to the limited boundary-layer moisture
    (generally 30s-40s F dewpoints) will promote strong downdrafts
    within established thunderstorms. The steep lapse rates and strong
    evaporative cooling may allow for a few stronger downdrafts with
    severe gusts possible. Some hail is also plausible owing to cooling
    mid-level temperatures, especially farther south and east where
    buoyancy is greater. Given the propensity for strong downdrafts,
    long-lived organized severe storms are unlikely.

    Confidence in sustained thunderstorm activity is highest across the
    central high Plains were synoptic ascent is more robust. However,
    strong heating and the dryline circulation could support at least
    isolated storm development farther south the TX/OK Panhandles this afternoon/evening. With the severe risk expected to remain isolated
    and short-lived, a WW currently appears unlikely.

    ..Lyons/Mosier.. 04/22/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!44vlFZbY7o7skYUB4Jg4B1cZnm_yztUUhT1mk-ndQJPWsS7FAaYuiBu9Ztqc3zWNQIA6zhcvg= FeAqpNT4G6A2S7qSNs$ for graphic product...

    ATTN...WFO...GID...LBF...DDC...UNR...GLD...AMA...PUB...BOU...
    CYS...

    LAT...LON 37790236 40310248 42850350 43390338 43650220 43450112
    43090076 41290003 39170047 37100084 36110151 35710209
    36250228 36810231 37790236=20

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


    =3D =3D =3D
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