• MESO: Mesoscale Discussion 1583

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Tue Aug 24 00:38:25 2021
    This is a multi-part message in MIME format...

    ------------=_1629765519-87341-2086
    Content-Type: text/plain
    Content-Transfer-Encoding: Quoted-printable

    ACUS11 KWNS 240038
    SWOMCD
    SPC MCD 240038=20
    SDZ000-NDZ000-240245-

    Mesoscale Discussion 1583
    NWS Storm Prediction Center Norman OK
    0738 PM CDT Mon Aug 23 2021

    Areas affected...Central South Dakota and southern North Dakota

    Concerning...Severe Thunderstorm Watch 458...

    Valid 240038Z - 240245Z

    The severe weather threat for Severe Thunderstorm Watch 458
    continues.

    SUMMARY...The severe thunderstorm threat continues across WW 458 in south-central South Dakota. A favorable environment for isolated
    strong to severe storms is developing across northern South Dakota
    and southern North Dakota. Trends are being monitored across this
    region.

    DISCUSSION...Latest radar trends from South Dakota show a few
    isolated cells ongoing within and on the periphery of WW 458. These
    storms have exhibited periods of supercellular characteristics with
    strong hail signatures (via MRSM MESH and vertically integrated ice
    estimates), though thunderstorm coverage has been limited with some
    weakening trends noted in the last half hour. This may be the result
    of somewhat weak forcing for ascent coupled with the onset of
    diurnal cooling. However, water vapor imagery suggests that stronger
    lift associated with an upper-level impulse remains upstream across
    CO/WY. Modest, but persistent, surface pressure falls over the High
    Plains over the past 2 hours support this idea and hint that more
    favorable broad-scale lift may overspread the region in the coming
    hours. Recent HRRR guidance loosely captures this scenario, which is
    supported by the aforementioned observed trends and points towards a continuation of the severe threat at least through the evening
    hours.=20

    Further north, gradual destabilization is noted as MUCAPE values
    increase to above 1000 J/kg along the ND/SD border due to low to
    mid-level moisture transport to the north/northwest. Weak convection
    moving out of northwest SD into this environment may undergo
    intensification given the favorable instability, strong deep layer
    shear (nearly 50 knots effective bulk shear sampled by the 00z BIS
    and ABR soundings), and increasing lift through the evening (via
    isentropic ascent in the 850-700 mb layer). While confidence in
    storm coverage is somewhat uncertain, convective trends in this area
    will be monitored.

    ..Moore.. 08/24/2021

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!sbgyk-FBC_d0G5Gr9PRZFmHRC2pvgydbtgr5SxDcEKeNI2Px46p2KbjJ1waHDnM_fkZuNt6O$=
    for graphic product...

    ATTN...WFO...FSD...ABR...BIS...UNR...

    LAT...LON 43300088 44070163 45490208 46320209 46630142 46710027
    46499941 45879860 45119809 44239802 43649806 43339853
    43029953 43300088=20



    ------------=_1629765519-87341-2086
    Content-Type: text/plain; charset="US-ASCII"
    Content-Disposition: inline
    Content-Transfer-Encoding: 7BIT

    = = =
    To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. ------------=_1629765519-87341-2086--

    --- SBBSecho 3.12-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)