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  • MESO: Mesoscale Discussion 1942

    From COD Weather Processor @1:2320/107 to All on Wed Aug 12 03:01:30 2026
    ACUS11 KWNS 120301
    SWOMCD
    SPC MCD 120300
    SDZ000-NEZ000-120430-

    Mesoscale Discussion 1942
    NWS Storm Prediction Center Norman OK
    1000 PM CDT Tue Aug 11 2026

    Areas affected...Parts of western into south-central SD and far
    northern NE

    Concerning...Severe Thunderstorm Watch 569...

    Valid 120300Z - 120430Z

    The severe weather threat for Severe Thunderstorm Watch 569
    continues.

    SUMMARY...A severe wind and hail risk may continue tonight into
    south-central South Dakota and vicinity, with downstream watch
    issuance possible.

    DISCUSSION...A well established supercell has gradually transitioned
    into a small bowing complex across western SD over the past hour or
    two, with mainly measured severe wind gusts up to around 75-80 mph.
    Even with the onset of nocturnal cooling, a reservoir of rich
    low-level moisture (with upper 60s to low 70s surface dewpoints) and
    steep mid-level lapse rates are supporting a narrow corridor of
    strong instability per latest mesoanalysis estimates. It is
    plausible that the ongoing small bow will track east-southeastward
    along the instability axis into south-central SD over the next few
    hours while continuing to pose a threat for severe gusts and hail.
    Time-lagged HRRR/RRFS runs support this scenario, with some members
    showing significant gust potential (75+ mph) persisting with
    eastward extent. Therefore, downstream watch issuance is being
    considered for parts of southern SD and far northern NE before the
    04Z expiration of Severe Thunderstorm Watch 569.

    ..Gleason/Mosier.. 08/12/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fjg!_lgOb8njsBUt3h14g-EWegjZBULMP0w87YPbAdlKXJHJ_OBkLHvm7DB_qQB-Bz3LgEbQFTUjMSRVCVI_UL1wzMzUmLA$ for graphic product...

    ATTN...WFO...FSD...ABR...LBF...UNR...

    LAT...LON 44090277 44620168 44400022 44149883 43639818 42909843
    42819932 42880113 43230277 43960281 44090277

    MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
    MOST PROBABLE PEAK WIND GUST...65-80 MPH
    MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)