Severe Thunderstorms Possible Today in VA/DC/MD

[VAWXWatcher6]

...DELMARVA/PA/NJ...
RESIDUAL WEDGE OF COOL/STABLE AIR PERSISTS IN THE LEE OF THE
APPALACHIANS THIS MORNING FROM PA SWD INTO NC. THE ERN EDGE OF THIS
AIRMASS HAS BEEN ERODING SLOWLY WITH HIGHER DEW POINTS IN THE 50S
AND 60S F DEVELOPING NWD ACROSS ERN VA INTO ERN NJ. LOW CLOUDS AND
FOG OVER INLAND AREAS SHOULD BURN OFF THROUGH THE MORNING BASED ON
LATEST SATELLITE IMAGERY SHOWING LITTLE IN THE WAY OF MID/HIGH
CLOUDINESS OVER THE REGION. INCREASING DOWNSLOPE FLOW AND MIXING
SHOULD STEEPEN LOW THROUGH MIDLEVEL LAPSE RATES AND CONTRIBUTE TO
THE DEVELOPMENT OF WEAK TO MODERATE INSTABILITY /SBCAPE 500-1500
J/KG/ BY AFTERNOON.

AS MIDLEVEL SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT CREST THE
APPALACHIANS AROUND 18Z...TSTMS ARE EXPECTED TO INITIATE OVER THE
HIGHER TERRAIN AND THEN MOVE GENERALLY EWD INTO STRONGER
INSTABILITY CENTERED OVER THE DELMARVA REGION THROUGH 21Z.
STRENGTHENING DYNAMIC FORCING FOR ASCENT WITHIN LEFT EXIT REGION OF
UPPER JET...AND POTENTIAL FOR LOW LEVEL CYCLOGENESIS WITHIN LEE
TROUGH SHOULD ALSO HELP SUSTAIN AND ENHANCE CONVECTION. DEEP LAYER
SHEAR OF 50-60KT WILL FAVOR SUPERCELLS BUT LINEAR FORCING AND
PREDOMINATELY UNIDIRECTIONAL DEEP LAYER FLOW SUGGESTS THE
DEVELOPMENT OF A BROKEN LINE OF SEVERE STORMS PRODUCING DAMAGING
WINDS...SOME LARGE HAIL...AND PERHAPS A TORNADO OR TWO. UNCERTAINTY
WITH RESPECT TO INSTABILITY CURRENTLY PRECLUDES AN UPGRADE TO MDT
RISK ACROSS THIS REGION. HOWEVER...IF GREATER INSTABILITY DOES
APPEAR LIKELY...A MDT RISK MAY BE NEEDED.

THREAT OF ISOLD LARGE HAIL FROM STORMS SLIGHTLY ELEVATED ABOVE THE
COOLER/MARITIME BOUNDARY LAYER COULD EXTEND FROM NJ EWD ACROSS THE
NYC AREA BY EVENING AS STEEPER LAPSE RATES AND FORCING WITH THE
UPPER WAVE MOVE ACROSS THESE AREAS.