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000
ACUS02 KWNS 110450
SWODY2
SPC AC 110449

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1149 PM CDT MON MAR 10 2014

VALID 121200Z - 131200Z

...NO SVR TSTM AREAS FORECAST...

...MIDDLE ATLANTIC...

INTENSE 12HR 500MB HEIGHT FALLS...IN EXCESS OF 200 M...WILL SPREAD
ACROSS THE OH VALLEY INTO THE NRN MIDDLE ATLANTIC DURING THE DAY
WEDNESDAY.  LATEST NAM IS MORE IN LINE WITH EARLIER GFS/ECMWF
REGARDING THE EVOLUTION/DEEPENING OF SFC LOW ACROSS SRN PA AFTER
18Z.  MODELS ARE IN GENERAL AGREEMENT THAT LOWER-MID 50S SFC DEW
POINTS SHOULD BE DRAWN NWD INTO PRE-FRONTAL WARM SECTOR WHICH SHOULD
CONTRIBUTE TO WEAK BUOYANCY ON THE ORDER OF 500 J/KG AT DIURNALLY
FAVORABLE TIME OF DAY...PRIMARILY ACROSS SRN PA...SWD INTO VA.
ADDITIONALLY...SFC-3KM LAPSE RATES ARE FORECAST IN EXCESS OF 7 C/KM
WHICH SHOULD ENCOURAGE ROBUST UPDRAFTS/DOWNDRAFTS WITHIN STRONGLY
SHEARED ENVIRONMENT.

LATEST THINKING IS SCT ELEVATED THUNDERSTORMS WILL BE ONGOING
ALONG/NORTH OF DEEPENING SFC CYCLONE OVER THE OH VALLEY AT THE
BEGINNING OF THE PERIOD.  THIS ACTIVITY SHOULD SPREAD/DEVELOP EWD
AHEAD OF STRONG PROGRESSIVE MID-LEVEL VORTICITY MAX.  BY EARLY
AFTERNOON SUFFICIENT HEATING SHOULD CONTRIBUTE TO NEAR-SFC BASED
UPDRAFTS ACROSS SWRN PA/NRN WV.  HAVE OPTED TO EXTEND 5 PERCENT
PROBABILITIES WWD TOWARD DEEPENING SFC LOW WHERE UPDRAFTS HAVE A
GREATER LIKELIHOOD OF ROOTING INTO BOUNDARY LAYER.  WIND FIELDS ARE
EXPECTED TO INCREASE MARKEDLY ACROSS THE DELMARVA DURING THE LATE
AFTERNOON AND THERE IS SOME CONCERN 50KT+ FLOW NEAR 900MB COULD MIX
TO THE SFC WITH STRONGER CONVECTIVE OUTFLOW.  WILL MAINTAIN LOW
SEVERE PROBS ACROSS THIS REGION PRIMARILY DUE TO FORECAST WEAK
INSTABILITY.  HOWEVER...HIGHER SEVERE PROBS MAY BE REQUIRED IF
CONFIDENCE INCREASES FOR A STRONGLY FORCED FRONTAL SQUALL LINE.

..DARROW.. 03/11/2014