• MESO: Mesoscale Discussion 0621

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Wed Apr 30 19:41:20 2025
    ACUS11 KWNS 301941
    SWOMCD
    SPC MCD 301940=20
    ILZ000-MOZ000-302145-

    Mesoscale Discussion 0621
    NWS Storm Prediction Center Norman OK
    0240 PM CDT Wed Apr 30 2025

    Areas affected...East-central Missouri into southern Illinois

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

    Valid 301940Z - 302145Z

    Probability of Watch Issuance...40 percent

    SUMMARY...A few storms are possible along an outflow boundary. All
    severe hazards would be possible. A watch is uncertain in the short
    term, but issuance is possible this afternoon depending on
    observational trends.

    DISCUSSION...Airmass modification after earlier convection has been
    evident over the past couple of hours in central Missouri and
    southern Illinois. The primary outflow boundary is situated just
    south of St. Louis and extends into far southern Illinois and
    southern Indiana. Dewpoints south of the boundary have increased to
    upper 60s F except for parts of southeastern Missouri which has only
    recovered into the low 60s F. North of the outflow boundary, stable
    billow clouds remain. However, very near the boundary temperatures
    and dewpoints have increased and at least some MLCIN has been
    removed and convection has begun to slowly deepen.

    With 40 kts of effective shear (more favorably oriented across the
    boundary on its western half), supercells would be expected if
    storms develop. Large hail and damaging winds would be possible. A
    tornado or two would also be possible for storms interacting with
    the more backed easterly/southeasterly winds on the cooler side of
    the boundary. Being in the wake of an earlier MCV, forcing for
    ascent will be nebulous and will depend on heating/destabilization
    along the outflow. Trends will continue to be monitored. A watch is
    possible this afternoon.

    ..Wendt/Hart.. 04/30/2025

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7OuZ8DkG5TzHBCRsVdnZnlOAROZOX4gavfH_kessXe8DNv0OvoUEdTDUQpISHI4rWZ-8Rvw66= Q71pnnDu6BqM3qL_uA$ for graphic product...

    ATTN...WFO...PAH...ILX...LSX...

    LAT...LON 38359140 38649151 39179104 39229055 38878972 38828868
    38808815 38618795 38168806 37928814 37538862 37558986
    38359140=20

    MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
    MOST PROBABLE PEAK WIND GUST...55-70 MPH
    MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


    =3D =3D =3D
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