MESOSCALE DISCUSSION 0643
   NWS STORM PREDICTION CENTER NORMAN OK
   0803 PM CDT WED APR 27 2011
   
   AREAS AFFECTED...WRN NY...CNTRL PA
   
   CONCERNING...TORNADO WATCH 236...
   
   VALID 280103Z - 280200Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 236 CONTINUES.
   
   TORNADO WATCH 236 IS SCHEDULED TO EXPIRE AT 02Z. HOWEVER...ONGOING
   TSTM ACTIVITY ALONG THE ERN PERIPHERY OF THE WW AND LEFT-SPLITS
   MOVING N/NEWD FROM CNTRL MD MAY NECESSITATE A WFO TEMPORAL EXTENSION
   OF THE WW BEYOND 02Z. ALTHOUGH OVERALL RADAR TRENDS SUGGEST ACTIVITY
   HAS RECENTLY PEAKED AND RECENT HRRR RUNS SUGGEST THIS TREND WILL
   CONTINUE...THE 00Z IAD RAOB SAMPLED A ROBUST SUPERCELL WIND PROFILE
   WHICH WILL SUPPORT AT LEAST A MARGINAL SEVERE THREAT THROUGH ABOUT
   03Z.
   
   ..GRAMS.. 04/28/2011
   
   
   ATTN...WFO...PHI...BGM...BUF...CTP...LWX...
   
   LAT...LON   39677759 40327751 42747683 43077673 43277639 42457606
               41327626 40267636 39697651 39677759