• DAY2 HIGH RISK MS/AL

    From Dumas Walker@21:1/175 to All on Fri Mar 14 18:14:00 2025
    ACUS02 KWNS 141731
    SWODY2
    SPC AC 141730

    Day 2 Convective Outlook
    NWS Storm Prediction Center Norman OK
    1230 PM CDT Fri Mar 14 2025

    Valid 151200Z - 161200Z

    ...THERE IS A HIGH RISK OF SEVERE THUNDERSTORMS IN CENTRAL/SOUTHERN
    PARTS OF MS/AL...

    ...SUMMARY...
    A tornado outbreak is likely on Saturday across the central Gulf
    Coast States and Deep South into the Tennessee Valley. Numerous
    significant tornadoes, some of which should be long-track and
    potentially violent, are expected on Saturday afternoon and evening.
    The most dangerous tornado threat should begin across eastern
    Louisiana and Mississippi during the late morning to afternoon,
    spread across Alabama late day into the evening, and reach western
    parts of the Florida Panhandle and Georgia Saturday night.

    ...Central Gulf Coast/Deep South/TN Valley...

    After collaboration with WFOs BMX/JAN/MOB, an upgrade to a level
    5-HIGH risk appears warranted for the most likely corridor of
    potentially violent tornadoes, peaking tomorrow afternoon and
    evening. A broader level 4-MDT risk has been expanded somewhat
    eastward for the nocturnal significant tornado threat.

    An intense mid-level jet, 100-110 kts at 500 mb, will eject through
    the basal portion of a broad southern Great Plains shortwave trough.
    This will induce secondary cyclogenesis along an initially
    slow-moving baroclinic zone from the Ark-La-Tex to the central Great
    Lakes. Another day of air mass modification ahead of this wave will
    yield a pronounced plume of rich northwest Gulf moisture that should
    be pristine across southeast LA and southern MS through late
    morning. As mid-level height falls overspread the diurnally warming
    air mass, increasing convective development is expected along the
    deepening baroclinic zone, as well as residual outflows to its
    northeast in the TN Valley from prior late D1 convection.

    Steep mid-level lapse rates atop the richly moist boundary layer
    will yield at least moderate MLCAPE from 1500-2500 J/kg across
    eastern LA into central MS. Vertically veering wind profiles with
    strong anvil-level divergence amid the favorable instability should
    support robust updrafts and intense supercells. Low-level shear will
    strengthen midday through the afternoon, yielding potential for a
    tornado outbreak.

    The most probable convective corridor will be along the effective
    outflow boundary across central/northern parts of MS into north AL
    and south TN. Along and south of this will be the most favored
    corridor for long-tracked, discrete supercells. These will likely
    develop within north/south-oriented confluence bands as increasing
    large-scale ascent becomes coincident with the peak heating cycle.
    A volatile combination of kinematic/thermodynamic parameters will
    support potential for long-track, EF3+ tornadoes. The overall
    spatial extent of this threat will be modulated by the degree of
    boundary-layer heating within the mid to upper 60s dew point plume,
    along with where exactly the large-scale outflow boundary sets up
    from late D1/early D2.

    Significant tornado potential, along with very large hail and
    destructive damaging wind gusts, should persist into Saturday night.
    Greater potential for a broken to linear band of thunderstorms is
    anticipated by this time, but wind profiles will still strongly
    favor supercells. As such, a mix of all three hazards may continue
    with sig severe hail potential favored south and sig severe wind
    favored north as the convective band spreads towards the southern
    Appalachians and the northeast Gulf Coast.

    ...OH Valley to central Great Lakes...

    Forecast confidence remains low with regard to severe potential
    north of the TN Valley. Guidance continues to differ on the degree
    of diurnal destabilization in the wake of the D1 shortwave trough
    and deep cyclone tracking into northern Ontario. With increasingly
    widespread Mid/Deep South to TN Valley thunderstorms during the day
    Saturday, the northward extent of appreciable surface-based
    instability appears highly questionable within a predominately
    meridional deep-layer wind profile. Given the fast flow regime
    though, even weak convection late afternoon through Saturday night
    will pose some risk for locally strong gusts and a tornado.

    ..Grams.. 03/14/2025

    $$
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