SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0254 PM CDT Thu Mar 31 2022
Valid 312000Z - 011200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS
OF EASTERN PENNSYLVANIA...CENTRAL MARYLAND...AND NORTHERN
VIRGINIA......
...SUMMARY...
Damaging thunderstorm gusts and a few tornadoes will remain possible
through this evening from parts of the Carolinas into the
Mid-Atlantic region and Hudson Valley.
...Mid Atlantic and Carolinas...
Scattered thunderstorm development along a subtle pre-frontal
confluence axis from central PA south into western VA and MD should
continue and increase this afternoon and evening with the passage of
an upper-level shortwave trough over northern NY. Marginal observed
surface moisture (dewpoints in the upper 50s to low 60s F) should
gradually improve ahead of these storms with dewpoints climbing into
the low 60s F by this evening. While cloud cover has forestalled
diurnal destabilization across eastern parts of PA and VA/MD so far,
cloud breaks and improving surface moisture agree with regional RAP
soundings showing the potential for weak destabilization (MLCAPE
250-500 J/kg) ahead of the developing storms farther west. VAD/VWPs
show very strong wind fields with 0-1km flow of 50-60 kts. Despite
the meager buoyancy and messy storm mode, bands of storms will be
capable of producing damaging wind gusts and perhaps a couple of
tornadoes as they move east into the ENH area and eventually
offshore this evening. For more info see MCD #378.
Farther south across the Carolinas and southern VA, early afternoon
thunderstorm development ahead of a speed max embedded within
southwesterly flow aloft should continue into this evening.
Widespread cloud cover has hampered diurnal destabilization
somewhat, but strong flow aloft and large clockwise curved
hodographs may support a continued risk for damaging gusts and a
tornado or two within linear bands and semi-discrete storms.
...Northern Florida into southeast Georgia...
A band of thunderstorms off the northwest FL coast should continue
to move east-northeast this afternoon and evening. Gradual weakening
of the system is expected as storms move away from large-scale
forcing for ascent and low-level surface flow veers. Damaging wind
gusts and a tornado or two will be possible with any stronger linear
segments or weak supercells able to develop. However, decreasing
buoyancy and ascent this evening should slowly diminish the severe
threat after sunset.
..Lyons/Gleason.. 03/31/2022
.PREV DISCUSSION... /ISSUED 1114 AM CDT Thu Mar 31 2022/
...VA into NY...
Broad and strong southwesterly flow aloft is present today across
much of the eastern US, with a strong shortwave trough moving across
the upper OH Valley. Breaks in the clouds are resulting in pockets
of heating across this area, which should yield at least marginal
afternoon CAPE values. Storms have begun to strengthen along a
pre-frontal axis over western PA. Model consensus shows multiple
corridors of strengthening low-level winds through the day, which
will help to enhance convergence and lead to more widespread
intensifying thunderstorms by mid-afternoon. These fast-moving
storms will pose a risk of damaging winds and isolated tornadoes.
Have added an ENH risk area for this threat.
...Southeast...
A broken line of thunderstorms extends from central GA into the FL
Panhandle this morning. The air mass ahead of the line is moist and
marginally unstable with dewpoints in the mid 60s to lower 70s and
MLCAPE values around 500 J/kg. Shear remains very strong across the
region, which may allow at least isolated cells to pose a damaging
wind and tornado threat for much of the day as the low-level jet
migrates northward into the Carolinas. Please refer to MCD #375 for
further details.
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