• DAY1 2/5 Risk Area Update

    From Mike Powell@618:250/10 to All on Fri Jun 12 13:09:02 2026
    ACUS01 KWNS 121632
    SWODY1
    SPC AC 121630

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    1130 AM CDT Fri Jun 12 2026

    Valid 121630Z - 131200Z

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
    AFTERNOON/EVENING ACROSS THE APPALACHIANS...MID-ATLANTIC AND
    NORTHEAST...AND THIS EVENING ACROSS THE SOUTHERN HIGH PLAINS...

    ...SUMMARY...
    Strong to severe storms capable of damaging winds are expected
    across parts of the Appalachians, Mid-Atlantic, and Northeast,
    mainly this afternoon and evening. Severe storms with a threat of
    large hail and severe wind gusts will also be possible across parts
    of the south-central High Plains.

    ...Mid-Atlantic into New England this afternoon/evening...

    Within the northern stream, a shortwave trough will progress
    east-northeastward over the lower Great Lakes this
    afternoon/evening, while an associated surface cold front moves
    eastward into New England and southeastward into the Mid-Atlantic.
    Forcing for ascent will not be particularly strong and the stronger
    midlevel flow/deep-layer vertical shear will remain displaced to the
    cool side of the front. Still, 25-30 kt midlevel flow will overlap
    the warm sector this afternoon from northern Chesapeake Bay
    northward into eastern NY. Strong surface heating is ongoing from
    the Piedmont into VA/southern PA, with a few more cloud patches from
    northeast PA into central NY. The net result will be moderate
    buoyancy (MLCAPE of 1000-2000 J/kg) in an environment with steep
    low-level lapse rates and weak upper flow, favoring multicell
    clusters with occasional wind damage. The weak forcing for ascent
    suggests that widely scattered, loosely organized clusters will be
    possible this afternoon, with some gaps in the wind threat.

    ...Southern High Plains late this afternoon into early tonight...

    Lee cyclogenesis across southeast CO will draw low-level moisture
    northwestward into the southern High Plains as a stalled front
    begins to lift northward across the TX Panhandle. Thunderstorm
    development is expected this afternoon/evening with upslope flow
    into the higher terrain of NM, and along the Raton Mesa. Deep-layer
    vertical shear/hodograph length will be sufficient for supercells
    initially off Raton Mesa, with large hail the primary threat. Some
    upscale growth and an increase in the potential for severe outflow
    gusts is expected late this evening as storms spread eastward toward
    southwest KS and the northern Panhandles in association with a
    nocturnal low-level jet and strengthened warm advection/moisture transport.

    ...Eastern KS/western MO early Saturday...

    In response to low-level warm advection and returning moisture,
    elevated convection is probable late in the period across eastern
    KS/western MO. This area will be near the east edge of the steep
    midlevel lapse rates, where isolated large hail will be possible.
    There will also be some potential for evolution into a cluster or
    two with isolated damaging gusts. Farther north into eastern NE
    (very near the end of the period) there will be a chance for
    elevated storms with some hail. This area will be re-evaluated this
    afternoon in the 20z update.

    ..Thompson/Chalmers.. 06/12/2026

    $$

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