MESOSCALE DISCUSSION 2212
   NWS STORM PREDICTION CENTER NORMAN OK
   0345 PM CDT WED SEP 28 2011
   
   AREAS AFFECTED...SERN PA...NERN MD...NRN DE
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 282045Z - 282145Z
   
   MARGINAL THREAT FOR ROTATING STORMS POSING A BRIEF TORNADO THREAT
   EXISTS ACROSS PORTIONS OF SERN PA...NERN MD AND NRN DE DURING THE
   NEXT FEW HOURS. HOWEVER...THE THREAT APPEARS TO BE TOO LIMITED TO
   SUPPORT WW ISSUANCE.
   
   AT 2030Z...SUBJECTIVE SURFACE ANALYSIS SHOWS A WARM FRONT LOCATED
   FROM SERN PA SEWD INTO DE. TEMPERATURES IN THE MID TO UPR 70S
   COMBINED WITH DEWPOINTS IN THE UPR 60S/LOW 70S ARE SUPPORTING MODEST
   INSTABILITY /MLCAPE VALUES FROM 500-1000 J PER KG/ DESPITE POOR
   LAPSE RATES. MODEST BOUNDARY LAYER HEATING/DESTABILIZATION HAS AIDED
   IN SEMI-DISCRETE THUNDERSTORM DEVELOPMENT OVER THE AREA DURING THE
   LAST FEW HRS. AS THESE CELLS LIFT NWD...THEY WILL ENCOUNTER A SHEAR
   ENVIRONMENT CHARACTERIZED BY ENLARGED LOW-LEVEL HODOGRAPH STRUCTURE
   AND 0-1 KM SRH RANGING FROM 100-200 M2 S-2. AS A RESULT...A FEW
   ROTATING STORMS MAY DEVELOP DURING THE MID TO LATE AFTERNOON AND
   POSE A MARGINAL THREAT FOR A BRIEF TORNADO. HOWEVER...GIVEN THE WEAK
   INSTABILITY AND LOW POTENTIAL FOR ORGANIZED STORM DEVELOPMENT...A WW
   DOES NOT APPEAR LIKELY.
   
   ..GARNER.. 09/28/2011
   
   
   ATTN...WFO...PHI...BGM...CTP...LWX...
   
   LAT...LON   40167504 39157565 39277683 40237716 40917701 41417635
               41147518 40167504