• MESO: Mesoscale Discussion 0790

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Fri May 28 22:55:52 2021
    This is a multi-part message in MIME format...

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

    ACUS11 KWNS 282255
    SPC MCD 282254=20

    Mesoscale Discussion 0790
    NWS Storm Prediction Center Norman OK
    0554 PM CDT Fri May 28 2021

    Areas affected...Parts of south central Texas into middle Texas
    coastal areas

    Concerning...Severe Thunderstorm Watch 218...

    Valid 282254Z - 290030Z

    The severe weather threat for Severe Thunderstorm Watch 218

    SUMMARY...A new severe thunderstorm watch likely will be needed by 7
    PM CDT, south of the current watch. Strong thunderstorm development
    posing a risk for large hail and locally damaging gusts will remain
    possible into early evening, with potential for the evolution of a
    larger, organizing cluster of storms while spreading southward this
    evening, accompanied by increasing risk for strong surface gusts.

    DISCUSSION...Individual storm motions have been relatively slow in
    the presence of modest to weak (around 20 kt) westerly deep-layer
    mean flow. However, due to pronounced veering of winds with height
    in lower to mid-levels, deep-layer shear remains strong and
    supportive of evolving supercell structures. Apparent moderate
    southeasterly low-level inflow into the stronger storms emanates
    from a seasonably moist boundary layer (lower to mid 70s dew
    points). Beneath steep mid-level lapse rates this is contributing
    to large mixed-layer CAPE on the order of 2000-4000 J/kg.=20=20

    Thermodynamic profiles are similar southward into the Rio Grande
    Valley and lower Texas coast, but with stronger capping beneath
    gradually warmer elevated mixed-layer air. However, a gradual southward/southwestward suppression of this elevated mixed-layer air
    is ongoing, which is expected to allow for a continued southward
    progression of convective development, in addition to an eastward
    and southeastward advection and propagation of cells into the 00-03Z
    time frame.=20=20

    A gradual consolidation of convective outflow/surface cold pools
    appears possible, which may contribute to further upscale convective
    growth and accelerating forward propagation, accompanied by
    increasing risk for damaging winds. Otherwise, large hail and
    localized potentially damaging wind gusts remains the primary threat
    into early evening.

    ..Kerr.. 05/28/2021

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!rLNNMD3vrBl9IzUpVJcdQkmGdTwvdNlGVihtAjULvBMMzUqEJLYbu6i2Yx3WIEy8Kn6t6SOg$=
    for graphic product...


    LAT...LON 30770018 30899898 30509696 29559514 28299645 28479800
    29480001 30390064 30770018=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. ------------=_1622242558-51543-2312--

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