MESOSCALE DISCUSSION 0652
   NWS STORM PREDICTION CENTER NORMAN OK
   0120 AM CDT THU APR 28 2011
   
   AREAS AFFECTED...CNTRL/ERN PA/NY
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 244...246...
   
   VALID 280620Z - 280715Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   244...246...CONTINUES.
   
   AS OF 0610Z...TSTMS HAVE EVOLVED INTO LARGELY A N/S-ORIENTED
   CLUSTER/BROKEN LINES WITH EMBEDDED SUPERCELL STRUCTURES FROM TIOGA
   COUNTY NY TO FULTON COUNTY PA. DOWNSTREAM AIR MASS DESTABILIZATION
   CONTINUES AS A VERY STRONG S/SWLY LLJ TRANSPORTS A RICH WARM THETA-E
   AIR MASS OVER THE MID-ATLANTIC. WITH SURFACE DEW POINTS IN THE
   MIDDLE 60S FIRMLY ENTRENCHED...THREATS FOR ISOLATED DAMAGING
   WINDS/TORNADOES WILL PERSIST GIVEN 0-1 KM SHEAR OF 40-50 KT. IF
   RADAR SIGNATURES APPEAR TO STRENGTHEN FURTHER...AN UPGRADE TO A
   TORNADO WATCH MAY BECOME NECESSARY.
   
   ..GRAMS.. 04/28/2011
   
   
   ATTN...WFO...OKX...ALY...PHI...BGM...BUF...CTP...LWX...
   
   LAT...LON   39887875 41767754 43207609 43737515 43727458 43607428
               43217408 42737401 42047421 40627529 39747619 39647732
               39757860 39887875