MESOSCALE DISCUSSION 1239
   NWS STORM PREDICTION CENTER NORMAN OK
   0456 PM CDT FRI JUN 19 2009
   
   AREAS AFFECTED...PARTS OF ERN OH / SWRN PA / NRN WV / FAR WRN MD
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 192156Z - 192300Z
   
   SEVERE POTENTIAL APPEARS TO BE INCREASING ACROSS PARTS OF ERN OH
   EXTENDING SEWD INTO THE E WV PANHANDLE.  A WW IS POSSIBLE.  
   
   RECENT RADAR MOSAIC SHOWS ORGANIZING SEVERE TSTM CLUSTER ACROSS
   N-CNTRL OH AS OF 2150Z AND IS PROBABLY AIDED BY
   CONVECTIVELY-ENHANCED VORTICITY MAXIMA LOCATED OVER NRN OH CRESTING
   THE UPPER RIDGE.  MESOANALYSIS SHOWS A WARM FRONT DRAPED FROM NERN
   OH SEWD INTO SWRN PA AND EXTENDING EWD TO CHESAPEAKE BAY.  FURTHER
   W...AN ELONGATED OUTFLOW BOUNDARY INTERSECTS POTENTIALLY TORNADIC
   SUPERCELL LOCATED OVER N-CNTRL IND.
   
   THE WARM SECTOR AIRMASS S OF THE DESCRIBED BOUNDARIES HAS BECOME
   EXTREMELY UNSTABLE ACROSS PORTIONS OF CNTRL OH /SURFACE-BASED CAPE
   EXCEEDING 4000 J/KG ACCORDING TO 18Z ILN RAOB AND RUC FORECAST
   SOUNDINGS/.  WITH STRONG WNWLY FLOW ALOFT...WILL FAVOR CONTINUED
   STORM ORGANIZATION AND INCREASED SEVERE POTENTIAL WITH TIME WITH THE
   STORMS MOVING SEWD ALONG EXISTING BAROCLINIC ZONE/INSTABILITY
   GRADIENT.  THE MAIN THREATS WITH THIS EVOLVING ACTIVITY WILL LIKELY
   BE A DMGG WINDS.
   
   ..SMITH.. 06/19/2009
   
   
   ATTN...WFO...CTP...LWX...PBZ...RLX...CLE...ILN...
   
   LAT...LON   38977999 39648150 40188231 40428260 40648253 40968229
               41108188 40988149 40718056 40117961 39827915 39377868
               39107882 38887910 38827934 38977999