• DAY2 4/5 RISK AREA POSTED

    From Mike Powell@618:250/10 to All on Sun Mar 15 15:11:12 2026
    ACUS02 KWNS 151732
    SWODY2
    SPC AC 151730

    Day 2 Convective Outlook
    NWS Storm Prediction Center Norman OK
    1230 PM CDT Sun Mar 15 2026

    Valid 161200Z - 171200Z

    ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN PARTS OF
    SOUTH CAROLINA...NORTH CAROLINA...VIRGINIA...MARYLAND...AND WASHINGTON D.C...

    ...SUMMARY...
    Widespread severe storms are anticipated on Monday across the
    Southeast and Mid-Atlantic States. Tornadoes, some strong, and
    particularly damaging winds are most likely from parts of South
    Carolina to Maryland during the afternoon.

    ...Synopsis...
    An expansive upper trough from WI to the Ark-La-Tex will further
    amplify as the basal portion pivots rapidly northeastward towards
    the Appalachians. A deep surface cyclone over Lower MI will progress
    into QC, with an occluded front arcing southward to a minor low over
    western to central NY by Monday afternoon. A sharp cold front will
    extend south of this low across the Southeast into the northeast
    Gulf, sweeping east across the entire Atlantic Seaboard by 12Z Tuesday.

    ...East...

    No change has been made to the ongoing level 4-MDT risk, with some
    expansion of the 3-ENH in GA, as well as expansions of 1-2/MRGL-SLGT
    across NY and FL. The highly meridional deep-layer flow regime
    suggests that surface-based instability appears more likely to
    develop into NY on Monday afternoon. This type of flow regime, along
    with substantial early-day convection south, both render some
    uncertainty on intensity amplitudes for wind/tornado across much of
    the ENH-MDT risk areas.

    A broken band of pre-frontal convection should be ongoing at 12Z
    Monday from the lee of the southern Appalachians to the FL
    Panhandle. The downstream environment will already be favorable for
    supercells including strong tornado potential. With mid to upper 60s
    surface dew points and initially modestly steep mid-level lapse
    rates, a plume of moderate buoyancy with MLCAPE of 1000-2000 J/kg
    should diurnally expand from north FL through at least SC. Any
    semi-discrete supercells in this environment will have the potential
    to produce a strong tornado and large hail through early afternoon
    before large-scale outflow likely shifts offshore of the GA/north FL coast.

    Destabilization farther north from NC to the DE Valley appears more
    uncertain, with potential for near-coastal convection within the
    low-level warm conveyor limiting more expansive/robust
    boundary-layer heating. A plume of weak MLCAPE up to 1000 J/kg
    should still develop across the Piedmont into parts of the coastal
    plain. Although flow fields will be highly meridional, they will be
    quite strong with an intense 700-mb jet strengthening across the
    Southeast behind the surface cold front. This will yield enlarged
    low-level hodograph curvature across much of the pre-frontal
    warm-moist sector.

    Even weak boundary-layer heating will be sufficient for
    intensification of an extensive QLCS from western to central
    portions of NY/PA southward through VA/NC towards midday/early
    afternoon. Embedded supercell structures should be most pronounced
    south, where breaks in the QLCS are more probable. Some of these
    could be long-track with sporadic strong tornadoes, in addition to
    the background widespread damaging winds anticipated with the QLCS.
    This activity will eventually interact with cool trajectories near
    the coastal Atlantic and should result in waning of severe potential
    in the Northeast near sunset.

    ..Grams.. 03/15/2026

    $$
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    * Origin: Capitol City Online (618:250/10)