• DAY1SVR: Moderate Risk OV

    From Mike Powell@618:250/1 to All on Tue Apr 2 07:46:00 2024
    ACUS01 KWNS 021233
    SWODY1
    SPC AC 021232

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0732 AM CDT Tue Apr 02 2024

    Valid 021300Z - 031200Z

    ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
    NORTHERN AND CENTRAL KENTUCKY...SOUTHEAST INDIANA...AND CENTRAL AND
    SOUTHERN OHIO...

    ...SUMMARY...
    A severe weather outbreak is possible today over the Ohio Valley
    with the broader severe weather risk including parts of the
    Southeast. Strong and potentially long-track tornadoes are possible
    from Indiana and Ohio southward into the Mid South. A threat for
    strong tornadoes may focus this evening into tonight across parts of
    Alabama and Georgia.

    ...Synopsis...
    A complex and strongly dynamic spring storm system will potentially
    result in a large area of severe-weather risk from the southern
    Great Lakes/OH Valley southward into portions of the Deep South,
    including AL/GA and the western Carolinas late tonight.

    A potent trough over the Upper Midwest this morning will evolve into
    a very strong mid-level low over the southwest Great Lakes by
    Wednesday morning. An intense mid-level speed max over northern
    Mexico/TX, in association with the southern portion of the
    larger-scale central U.S. trough, will rapidly move east-northeast
    during the period and intensify to 125-kt at 500 mb over the
    southern Appalachians by daybreak Wednesday. Intense 12-hr midlevel
    height falls are forecast across much of the Great Lakes, OH/TN
    Valley, and the northern Gulf States, where values in excess of 200m
    are expected during the latter half of the period. The synoptic
    front this morning is draped across the OH Valley and will likely
    advance north due to the digging trough.

    ...OH Valley...
    Water-vapor imagery loop overnight showed a southern-stream
    short-wave trough associated with this morning's severe thunderstorm
    activity straddling the OH River in central KY and southern IN.
    This early-day thunderstorm complex will probably pose a risk for
    wind damage and perhaps a couple of tornadoes before it moves into
    the central Appalachians towards midday (see MCD #341 for short-term
    details). In its wake, a trailing outflow boundary/effective warm
    frontal zone will likely advance northward into IN/OH later today
    with lower to mid 60s progged to near I-70. Models continue to show
    an appreciable window of opportunity in which cloud breaks/heating
    and increasing low-level moisture contribute to moderate
    destabilization during the afternoon. Have adjusted the western
    envelope of severe probabilities farther west across IN to account
    for greater destabilization than earlier forecast, but otherwise
    have left the outlook unchanged across the OH Valley. Scattered
    thunderstorms will likely develop by early to mid afternoon with
    discrete supercells evolving from the more intense updrafts.
    Tornadoes, large to very large hail, and damaging gusts are expected
    with the supercells that mature across the warm sector. Enlarged
    and elongated hodographs imply fast storm motions and the
    possibility for several cyclic tornadic supercells, some of which
    may yield strong and long-lived tornadoes.

    Farther east, strong to severe storms may continue across the
    central Appalachians and perhaps move east into the Mid-Atlantic
    states. Hail/wind appear to be the primary hazards with this
    activity.

    ...Southeast this evening/tonight...
    Farther south and initially in the TN/MS/northern AL vicinity,
    severe thunderstorms are forecast to develop this afternoon as the
    leading edge of stronger large-scale ascent impinges on the region.
    A moisture-rich airmass and wind profile favoring supercells, will
    favor a risk for all severe hazards with the stronger thunderstorms.
    Although it remains unclear with regard to daytime to evening storm
    evolution across MS/AL/TN, the approach of the 500-mb speed max and
    intense shear through a deep layer atop a moist/unstable boundary
    layer, suggest a bimodal severe threat will probably evolve this
    evening into the overnight. Model guidance indicates messy but
    organized storm modes within a larger area of convection will
    probably develop. Forecast soundings show 300-500 m2/s2 0-1 km SRH
    from central/eastern AL into GA during the evening and overnight.
    The risk for tornadoes, including a few strong tornadoes, will be
    possible with this activity eventually reaching the Carolinas and
    the eastern FL Panhandle late.

    ..Smith/Leitman.. 04/02/2024

    $$
    --- SBBSecho 3.20-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)