MD 0993 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PORTIONS OF FAR SOUTHEAST NEW YORK…EASTERN PENNSYLVANIA…NEW JERSEY…DELAWARE…EASTERN MARYLAND…FAR EASTERN VIRGINIA
Mesoscale Discussion 0993
NWS Storm Prediction Center Norman OK
1130 AM CDT Mon Jun 12 2023
Areas affected...Portions of far southeast New York...eastern
Pennsylvania...New Jersey...Delaware...eastern Maryland...far
eastern Virginia
Concerning...Severe potential...Watch possible
Valid 121630Z - 121730Z
Probability of Watch Issuance...40 percent
SUMMARY...The severe threat will gradually increase across portions
of the Mid Atlantic this afternoon. Damaging gusts are the main
concern, though an instance or two of large hail and perhaps a brief
tornado cannot be ruled out. A Severe Thunderstorm Watch issuance is
possible.
DISCUSSION...A corridor of insolation ahead of a broad stratiform
rain band (associated with an upper trough) has supported surface
temperatures rising into the upper 70s/lower 80s F, with upper 60s F
dewpoints contributing to 1000-2000 J/kg of thin MLCAPE (given poor
mid-level lapse rates). While increasing deep-layer ascent atop the
mixing boundary layer will support an increase in convective
coverage, deep-layer shear is expected to remain modest, with
slightly curved/elongated hodographs supporting multicellular
development amid 30 kts of effective bulk shear. With low-level
lapse rates steepening to over 7 C/km, damaging gusts appear to be
the main threat with the stronger storms. Given the modest hodograph
curvature, an instance or two of marginally severe hail is possible
and a tornado cannot be completely ruled out. Conditions will
continue to be monitored for corridors of locally stronger surface
heating, which may support enough coverage of damaging-gust
producing storms to warrant a Severe Thunderstorm Watch issuance.
..Squitieri/Thompson.. 06/12/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...LWX...
LAT...LON 36627772 38357657 40057573 41627472 41747413 41677385
41457366 40847375 40127406 39387455 38327515 37477568
36937599 36717619 36607679 36627772
