SPC AC 231244
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0644 AM CST Wed Feb 23 2022
Valid 231300Z - 241200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected today or tonight.
...Synopsis/Discussion...
In mid/upper levels, deep troughing predominates over the western
CONUS, with intermittently closed cyclonic flow centered over NV.
The synoptic trough will lose some amplitude through the period, but
remain strong and well-defined, as it moves eastward to a position
at 12Z tomorrow from eastern WY to central CO, the Four Corners
area, and southwestern AZ/northern Baja. Marginal low/middle-level
moisture, favorable large-scale DCVA/lift, related steep midlevel
lapse rates, and resulting weak buoyancy will promote isolated
thunderstorm potential in a corridor of cyclonic flow from southern
CA to the Four Corners.
Downstream southwesterly flow will prevail over the central CONUS,
gradually becoming westerly with eastward extent into the Atlantic
Coast States. A weak/embedded shortwave trough -- initially located
over parts of northeast TX to southeastern NM and far west TX --
will eject northeastward rapidly, reaching parts of KY by 00Z, and
NJ by 12Z in a much-weakened condition. Until then, associated
low-level warm/moist advection to its east and south -- elevated
atop an intense post-frontal cold/stable layer where north of the
frontal zone described below -- will support sporadic thunder. This
will include bouts of lightning accompanying sleet and freezing rain
from an ongoing/expanding episode over north-central/northwest TX
and southern OK, across more of OK/AR through afternoon. Forecast
soundings suggest 200-700 J/kg MUCAPE may develop over the cold-
frontal layer, and isolated subsevere hail may occur in the most
intense cores already yielding sleet and freezing rain.
At the surface, a cold front was drawn at 11Z from the Adirondacks
across central PA, southwestern VA, eastern TN, northwestern AL,
southwestern MS, to near GLS and LRD, across northern Coahuila and
northeastern Chihuahua, to central/north-central NM. By 00Z, this
boundary should extend from the Delmarva Peninsula to central/
southwestern GA, southern portions of AL/MS/LA, and just offshore
from most of the TX Coast, to near BRO. By 12Z, the front should
move little from LA southwestward while retreating inland across
central and perhaps northern parts of MS/AL/GA.
..Edwards/Gleason.. 02/23/2022
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