MESOSCALE DISCUSSION 0885
   NWS STORM PREDICTION CENTER NORMAN OK
   0354 PM CDT THU MAY 28 2009
   
   AREAS AFFECTED...PORTIONS OF THE UPPER OH VALLEY TO THE UPPER TN
   VALLEY
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 313...
   
   VALID 282054Z - 282200Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 313
   CONTINUES.
   
   AS OF 2045Z...RADAR/SATELLITE IMAGERY INDICATED STRONGER CONVECTIVE
   ACTIVITY WAS LOCATED ALONG THE NRN AND SRN PERIPHERY OF WW 313 OVER
   THE UPPER OH AND LOWER TN VALLEYS. THE NRN ACTIVITY CONSISTED MAINLY
   OF SHORT-LINE SEGMENTS WITH MORE CELLULAR ELEMENTS FARTHER S.
   HEATING/DESTABILIZATION WANES WITH NRN EXTENT...ALTHOUGH THIS HAS
   BEEN COMPENSATED BY MORE ROBUST FORCING ASSOCIATED WITH A MID-LEVEL
   IMPULSE EJECTING TOWARDS THE UPPER OH VALLEY. INCREASING
   HIGHER-LEVEL WINDS HAVE BEEN NOTED IN TIME-SERIES TRENDS AT
   CHARLESTON WV VAD PROFILER...WHICH SHOULD AID IN MAINTAINING OR EVEN
   ENHANCING LINEAR ORGANIZATION GIVEN LARGELY UNIDIRECTIONAL PROFILES.
   DAMAGING WINDS SHOULD BE THE PRIMARY THREAT FOR THE NEXT FEW HOURS
   AS INDIVIDUAL CLUSTERS LIKELY EVOLVE NEWD. OVERALL THREAT DOES NOT
   APPEAR SUFFICIENT FOR AN ADDITIONAL WW N OF WW 313...BUT TRENDS WILL
   CONTINUE TO BE MONITORED.
   
   FARTHER SW...UPDRAFTS HAVE GENERALLY STRUGGLED TO MAINTAIN SEVERE
   INTENSITY DESPITE GREATER INSTABILITY. THE LACK OF STRONGER
   LARGE-SCALE ASCENT MAY BE A LIMITING FACTOR. HOWEVER...WITH APPROACH
   OF UPSTREAM COLD FRONT /FROM MIDDLE TN TO NWRN AL/...AN INCREASE IN
   CONVECTIVE INTENSITY/COVERAGE MAY YET OCCUR.
   
   ..GRAMS.. 05/28/2009
   
   
   ATTN...WFO...BGM...BUF...CTP...RNK...PBZ...RLX...CLE...GSP...
   MRX...JKL...FFC...OHX...
   
   LAT...LON   36478453 38678249 40328118 41637985 42567874 42407778
               42047751 41257791 40207861 38438015 37558078 36728135
               35938204 35148266 34648339 34848374 34938454 35068554
               35398568 36478453