Mesoscale Discussion 1822
NWS Storm Prediction Center Norman OK
0923 AM CDT Sun Sep 25 2022
Areas affected...Eastern WV...Southwest/South-Central
PA...Western/Central MD...Northern VA
Concerning...Severe potential...Watch possible
Valid 251423Z - 251630Z
Probability of Watch Issuance...60 percent
SUMMARY...Thunderstorm coverage is expected to gradually increase
from eastern WV/southwest PA eastward into south-central PA,
northern VA, and western/central MD over the next few hours. Bowing
line segments capable of damaging wind gusts are possible, and a
watch may be needed to cover this severe potential.
DISCUSSION...Visible satellite imagery shows modest clearing across
northern WV and adjacent south-central PA, in between a southwest to
northwest oriented stratus band and more agitated/vertically
developed clouds farther west. The strongest storm currently ongoing
developed along the leading edge of the westernmost cloudiness,
which appears to be associated with ascent attendant to a speed max
moving through the westerly flow aloft.
Expectation is for additional storm development in a similar
pattern, with the air mass destabilizing amid the brief heating just
ahead of this ascent. As such, the air mass is only expected to be
modestly buoyant. However, the limited buoyancy will likely be
compensated somewhat by the moderate to strong mid-level flow moving
over the region. Current mesoanalysis estimates 0-3 km bulk shear
from 40 to 50 kt, which is supported by the recent PBZ and CTP VADs
which sampled 51 kt and 46 kt, respectively. These kinematic
conditions will support a threat for damaging gusts with bowing line
segments as the ascent moves eastward throughout the afternoon.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 39678006 40477855 40537751 40247707 39247667 38407740
38457934 38968032 39678006