Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1144 PM CST Sat Dec 02 2023
Valid 031200Z - 041200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER WESTERN
PENNSYLVANIA...
...SUMMARY...
Isolated severe thunderstorms capable of hail and/or damaging wind
gusts are possible over western Pennsylvania this afternoon.
...Synopsis...
Shortwave trough traversing KS/OK early Sunday morning is expected
to progress northeastward across the Mid MS and OH Valleys today,
before then continuing through the Northeast overnight. Another
substantial shortwave trough will follow in the wake of the first,
moving through the central Plains and Mid MS Valley by early Monday
morning.
Surface pattern early Sunday morning features a low over eastern
KY/TN vicinity, with a cold front extending from this low back
southwest from the low across northern and western AL, and southern
MS. This low is forecast to progress north-northeastward throughout
the day, deepening as it does. At the same time, the cold front is
expected to make steady eastward progress across AL, GA, and much of
the FL Peninsula. Expectation is for the front to be off the
Southeast coast and through much of the northern and central FL by
early Monday morning. Thunderstorms are possible along this front,
as well as preceding outflow. Moderate mid-level flow will be in
place, but the stronger flow aloft will lag behind these showers and
thunderstorms. Additionally, buoyancy will be tempered by modest
lapse rates. These factors should limit the overall storm strength
and keep severe potential low.
...Upper OH Valley...
Despite early period cloudiness and showers, the airmass across the
Upper OH Valley is expected to destabilize by the afternoon, with
temperatures likely reaching the low to mid 50s across western PA.
Low-level moisture will be modest, with dewpoints likely in the
upper 40s/low 50s. Even so, steep low-level lapse rates coupled with
cooling temperatures aloft should result in modest buoyancy ahead of
the approaching shortwave trough. Strong ascent attendant to this
shortwave is expected foster thunderstorm development as it
interacts with this limited buoyancy. Low-level flow will be modest,
but strong mid and upper-level flow will encourage fast storm
motions and the potential for a few stronger gusts with any robust
storms. Given the cold mid-level temperatures and strong deep-layer
shear, some hail is possible as well.
..Mosier/Thornton.. 12/03/2023
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