MESOSCALE DISCUSSION 0659
   NWS STORM PREDICTION CENTER NORMAN OK
   0536 PM CDT FRI MAY 01 2009
   
   AREAS AFFECTED...PORTIONS OF OH AND WRN PA
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 012236Z - 012330Z
   
   THUNDERSTORMS...SOME STRONG TO SEVERE...WILL CONTINUE TO DEVELOP
   ACROSS PORTIONS OF OH AND WRN PA OVER THE NEXT FEW HOURS. PRIMARY
   THREATS OF HAIL/WIND CAN BE EXPECTED...ALTHOUGH DUE TO THE
   MARGINAL/ISOLD NATURE OF STRONGER STORMS...A WW IS NOT ANTICIPATED.
   
   THUNDERSTORMS HAVE DEVELOPED ALONG A SURFACE COLD FRONT AHEAD OF A
   POSITIVELY TILTED TROUGH TO THE WEST. ALTHOUGH AMPLE CLOUD COVER HAS
   SOMEWHAT LIMITED STRONGER SURFACE HEATING...POCKETS OF
   CLEARING...AND DEW POINTS IN THE UPPER 50S/LOWER 60S HAVE ALLOWED A
   NARROW AXIS OF MARGINAL INSTABILITY TO DEVELOP. PROFILER DATA ACROSS
   THE REGION SHOW NEARLY UNIDIRECTIONAL WIND FIELDS ORIENTED ROUGHLY
   PARALLEL TO THE FRONT...WHICH WILL SOMEWHAT HINDER INDIVIDUAL CELLS
   AND FAVOR BROKEN LINES OF CONVECTION. DESPITE ADEQUATE 0-6 KM BULK
   SHEAR NEAR 35 KTS...WEAK LAPSE RATES WILL LIMIT OVERALL SEVERITY OF
   STORMS...WITH MAINLY MARGINALLY SEVERE HAIL EXPECTED. STRONG WINDS
   MAY ACCOMPANY COLLAPSING CELLS AS 30 TO 35 KT LOW LEVEL WINDS MIXING
   TO THE SURFACE ARE ENHANCED BY EVAPORATIONAL COOLING.
   
   ..HURLBUT.. 05/01/2009
   
   
   ATTN...WFO...CTP...PBZ...RLX...CLE...ILN...
   
   LAT...LON   39708132 39478283 40098303 40628172 41428020 41857916
               41517836 40717915 40008055 39708132