MESOSCALE DISCUSSION 0622
   NWS STORM PREDICTION CENTER NORMAN OK
   0121 PM CDT FRI MAY 10 2013
   
   AREAS AFFECTED...ERN OH...WV...WRN PA...EXTREME WRN NY
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 101821Z - 101915Z
   
   PROBABILITY OF WATCH ISSUANCE...40 PERCENT
   
   SUMMARY...MARGINALLY SEVERE WIND GUSTS WILL ACCOMPANY ORGANIZING
   SQUALL LINE AS IT PROGRESSES ACROSS THE OH VALLEY.
   
   DISCUSSION...LONG-LIVED MCS WITH AN EXPANSIVE AREA OF POST SQUALL
   LINE PRECIPITATION IS SPREADING ACROSS THE OH VALLEY EARLY THIS
   AFTERNOON.  LATEST RADAR DATA SUGGESTS CENTER OF OLD MCV IS SHEARING
   NEWD ACROSS KY...CURRENTLY LOCATED ABOUT 40 SE OF SDF.  STRONG
   BOUNDARY LAYER HEATING ACROSS ERN OH INTO WRN PA HAS CONTRIBUTED TO
   STEEP SFC-3KM LAPSE RATE ENVIRONMENT AND THIS APPEARS PARTLY
   RESPONSIBLE IN RECENT RASH OF ISOLATED CONVECTION AHEAD OF MATURING
   SQUALL LINE.  GIVEN THE MODEST SWLY DEEP LAYER FLOW THERE IS REASON
   TO BELIEVE SQUALL LINE WILL ADVANCE ACROSS ERN OH/NRN WV AT ROUGHLY
   30-35KT REACHING WRN PA LATE THIS AFTERNOON.  MARGINALLY SEVERE WIND
   GUSTS ARE THE GREATEST SEVERE THREAT WITH THIS ACTIVITY AND MOST
   CONVECTION IS EXPECTED TO PRODUCE GUSTS LESS THAN 40KT.
   
   ..DARROW/CARBIN.. 05/10/2013
   
   
   ATTN...WFO...BUF...CTP...LWX...PBZ...RLX...CLE...ILN...
   
   LAT...LON   40298283 41528157 42347869 40427773 37818139 40298283