• MESO: Mesoscale Discussion 1857

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Thu Oct 14 00:50:46 2021
    This is a multi-part message in MIME format...

    Content-Type: text/plain
    Content-Transfer-Encoding: Quoted-printable

    ACUS11 KWNS 140050
    SPC MCD 140050=20

    Mesoscale Discussion 1857
    NWS Storm Prediction Center Norman OK
    0750 PM CDT Wed Oct 13 2021

    Areas affected...Parts of Deep South Texas and the adjacent lower
    Rio Grande Valley

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

    Valid 140050Z - 140245Z

    Probability of Watch Issuance...20 percent

    SUMMARY...Increasing thunderstorm development near and just east of
    the Interstate 35 corridor of Deep South Texas will intensify
    further during the next few hours, and perhaps occasionally pose a
    risk for severe hail and locally strong surface gusts. It seems
    unlikely that a severe weather watch will be needed, but trends will
    continue to be monitored.

    DISCUSSION...Warm elevated mixed-layer air has suppressed deep
    convective development into early evening across the lower Rio
    Grande Valley, but thunderstorms are now initiating around Laredo
    northward into the San Antonio area. It appears that this is being
    supported by another mid-level perturbation emerging from the
    Mexican Plateau, which is forecast to be accompanied by substantive
    mid-level cooling overspreading the Rio Grande River vicinity
    through a corridor along and east of Interstate 35 between now and
    03-05Z. This will coincide with a narrow plume of tropical moisture
    return (including PW of 2-2.25+ inches) from the the western Gulf of
    Mexico, which is contributing to large CAPE in the presence of
    modestly steep mid-level lapse rates.

    Given this thermodynamic environment, shear associated with a belt
    of 30-40 kt south-southwesterly flow in the 700-500 mb layer may be
    sufficient to support the evolution of a few supercell structures.=20
    While modest to weak southerly lower-level flow probably will remain
    a limiting factor concerning the overall severe weather potential,
    stronger cells might still be able to occasional pose a risk for
    severe hail hail and locally strong surface gusts.

    ..Kerr/Guyer.. 10/14/2021

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!o2icXU-g89B6RxskoE335av-MWzPhVNYC026mRLsnigM-TC_lPKRlbsnXLnsEGTJ08RKs7aB$=
    for graphic product...


    LAT...LON 27169964 28419938 29389882 30029835 29819768 28519822
    27169862 26059930 27169964=20

    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. ------------=_1634172652-54005-2869--

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