• MESO: Mesoscale Discussion 2255

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Fri Oct 20 18:46:12 2023
    ACUS11 KWNS 201846
    SWOMCD
    SPC MCD 201845=20
    SCZ000-NCZ000-GAZ000-202115-

    Mesoscale Discussion 2255
    NWS Storm Prediction Center Norman OK
    0145 PM CDT Fri Oct 20 2023

    Areas affected...Northeast GA...western/central SC...and southwest/south-central NC

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

    Valid 201845Z - 202115Z

    Probability of Watch Issuance...20 percent

    SUMMARY...Thunderstorms should gradually increase in coverage and
    intensity through the afternoon. Isolated strong to severe gusts and
    marginal hail are possible. A watch is not expected.

    DISCUSSION...During the next few hours, increasing thunderstorm
    development is expected along/east of the southern Appalachians, as
    a cold front continues east-southeastward into the area. This
    activity will be aided by strengthening upper-level divergence in
    the left exit region of a robust mid/upper-level jet crossing the
    OH/TN Valleys. While pre-convective instability will remain
    marginal, boundary-layer heating/mixing in the wake of earlier
    convection, coupled with steepening low/mid-level lapse rates, will
    yield sufficient instability for isolated to widely scattered
    low-topped thunderstorms. Strengthening mid/upper-level westerlies
    associated with the approaching jet max will contribute to 30-45 kt
    of effective shear -- characterized by a mostly straight hodograph.=20

    As a result, several loosely organized clusters/line segments and
    perhaps transient low-topped supercell structures are possible
    through the afternoon. Strong to locally severe gusts (50-60 mph)
    and marginal hail (up to 1 inch diameter) could accompany the
    more-organized storms. However, the weak instability and veered
    pre-frontal low-level winds should generally limit storm intensity,
    and a watch is not currently expected.

    ..Weinman/Guyer.. 10/20/2023

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!4Lz1vxP8QczRQ7KvApxDUeTxZ8BchI9Qia_RdWkQJlr-njeUKg3sfjzpdaaA52ZlaR_zleZak= eK_amFD0Ht9xaQdxBk$ for graphic product...

    ATTN...WFO...RAH...CAE...GSP...FFC...

    LAT...LON 34158329 34618302 35408200 35798117 35818075 35618025
    35128023 34828030 34428046 33868101 33498162 33338226
    33308285 33418320 33748334 34158329=20


    =3D =3D =3D
    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.

    --- SBBSecho 3.14-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)