MESOSCALE DISCUSSION 0586
   NWS STORM PREDICTION CENTER NORMAN OK
   1218 PM CDT TUE APR 26 2011
   
   AREAS AFFECTED...PARTS OF THE CNTRL APPALACHIANS...UPPER
   MID-ATLANTIC
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 261718Z - 261815Z
   
   TSTM COVERAGE WILL LIKELY INCREASE THROUGH THE AFTERNOON WITH
   ATTENDANT RISKS FOR DAMAGING WINDS...SEVERE HAIL...AND AN ISOLATED
   TORNADO OR TWO. THE PROBABILITY OF A WW ISSUANCE BY 19Z IS 80
   PERCENT.
   
   WITHIN A BROAD WARM SECTOR IN PLACE ACROSS THE UPPER OH VALLEY
   THROUGH THE NRN/CNTRL APPALACHIANS...A COUPLE OF N/S CONFLUENT AXES
   HAVE FOSTERED DISCRETE CELL DEVELOPMENT FROM SWRN NY TO CNTRL PA AND
   ACROSS THE NRN WV PANHANDLE INTO SWRN PA. MORNING RUNS OF THE
   HRRR/WRF-NMM AND 00Z WRF-NSSL ALL SUGGEST UPSCALE GROWTH WILL OCCUR
   THROUGH THE AFTERNOON AS CONTINUED HEATING LEADS TO WEAK/MODERATE
   INSTABILITY AND FORCING PERSISTS DOWNSTREAM OF UPPER GREAT LAKES
   SHORT WAVE TROUGH. GIVEN 35 TO 45 KT EFFECTIVE SHEAR...ORGANIZED
   CLUSTERS WITH EMBEDDED SUPERCELL STRUCTURES APPEAR
   LIKELY...PRIMARILY PRODUCING DAMAGING WINDS AND SEVERE HAIL.
   
   ..GRAMS.. 04/26/2011
   
   
   ATTN...WFO...ALY...BGM...BUF...CTP...LWX...PBZ...RLX...
   
   LAT...LON   39877731 39077856 38877997 39328086 40598040 42627860
               43377648 43417539 43127457 42847451 42447473 40857633
               39877731