MESOSCALE DISCUSSION 1923
   NWS STORM PREDICTION CENTER NORMAN OK
   0731 PM CDT TUE AUG 09 2011
   
   AREAS AFFECTED...OH...SRN IND...NWRN PA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 753...758...
   
   VALID 100031Z - 100200Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   753...758...CONTINUES.
   
   DAMAGING WIND AND MARGINAL HAIL THREATS SHOULD CONTINUE NEXT COUPLE
   OF HOURS WITH CLUSTERS/SHORT-LINE SEGMENTS PROGRESSING E/SEWD AHEAD
   OF COLD FRONT. HOWEVER...SEVERE THREAT WILL LIKELY DECREASE AFTER
   SUNSET AND THE NEED FOR A NEW WW ACROSS SRN OH/IND IS UNCLEAR BEYOND
   02Z SCHEDULED EXPIRATION OF WW 753.
   
   00Z SURFACE ANALYSIS PLACED COLD FRONT AROUND 40 E TOL SWWD TO NEAR
   IND. TSTMS HAVE GROWN UPSCALE INTO SHORT-LINE SEGMENTS/CLUSTERS AND
   RACED AHEAD OF THE FRONTAL BOUNDARY. MEASURED SEVERE WIND GUSTS AND
   WIND DAMAGE REPORTS HAVE OCCURRED THE PAST FEW HOURS AND SEVERE
   POTENTIAL IS LIKELY AT OR NEAR PEAK. MODIFIED 00Z ILN RAOB SUGGESTS
   BUOYANCY IS MODEST WITH MLCAPE NEAR 1000 J/KG AND AS BOUNDARY LAYER
   STABILIZATION INCREASES...THE STRENGTH OF DOWNDRAFTS SHOULD
   WANE...MORE RAPIDLY SO AFTER SUNSET. UNTIL THAT TIME...THE NEARLY
   UNIDIRECTIONAL AND STRONG FLOW AOA 2 KM AGL...WILL MAINTAIN
   ORGANIZED LINEAR/SUPERCELL STRUCTURES AND ATTENDANT PRIMARY THREAT
   OF DAMAGING WINDS.
   
   ..GRAMS.. 08/10/2011
   
   
   ATTN...WFO...BUF...PBZ...RLX...CLE...ILN...LMK...IND...
   
   LAT...LON   39378679 39748564 40418403 41028263 41678154 42018052
               42137994 41997974 41437973 40418050 39478267 39028397
               38908473 38928579 39068650 39378679