MESOSCALE DISCUSSION 0624
   NWS STORM PREDICTION CENTER NORMAN OK
   1224 PM CDT WED APR 27 2011
   
   AREAS AFFECTED...FAR ERN OH...NRN WV...WRN/CNTRL PA...WRN NY
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 271724Z - 271900Z
   
   PORTIONS OF FAR ERN OH...NRN WV...WRN/CNTRL PA AND WRN NY WILL
   LIKELY REQUIRE A WW ISSUANCE DURING THE EARLY AFTERNOON.
   
   MESOANALYSIS AT 17Z SHOWS SURFACE LOW PRESSURE MOVING NWD ACROSS
   LOWER MI IN ASSOCIATION WITH FAST MOVING UPPER IMPULSE LIFTING INTO
   THE GRT LKS REGION. VISIBLE SATELLITE IMAGERY SHOWS CLEAR SKIES
   ACROSS THE AREA...WITH INCREASE IN CUMULUS GROWTH AHEAD OF
   CONVECTIVE LINE OVER CNTRL OH. SURFACE TEMPERATURES HAVE QUICKLY
   WARMED THROUGH THE 70S TO LOW 80S...AIDING IN STRONG BOUNDARY LAYER
   DESTABILIZATION. THOUGH SURFACE DEWPOINTS ARE SOMEWHAT MARGINAL
   /UPPER 50S F/...RUC FORECAST SOUNDINGS INDICATE MLCAPE VALUES WILL
   RESIDE AROUND 1000 J/KG BY PEAK HEATING. THIS INSTABILITY WILL BE
   FAVORABLE FOR SVR STORMS GIVEN VERY STRONG VERTICAL WIND SHEAR
   PROFILES PRESENT ACROSS THE REGION /0-1 KM SRH IN EXCESS OF 200 M2
   S-2...AND EFFECTIVE BULK SHEAR VALUES AROUND 50 KT/. LATEST 3KM HRRR
   INDICATES THUNDERSTORMS MAY EVOLVE OUT OF THE CONVECTIVE LINE MOVING
   TOWARD ERN OH BY 19Z...WITH PRE-LINE/WARM SECTOR ACTIVITY ALSO
   POSSIBLE OVER WRN/CNTRL PA. THE STRONG WIND FIELDS SHOULD SUPPORT
   THE DEVELOPMENT OF SUPERCELLS AND FAST MOVING LINE SEGMENTS...WHICH
   WILL POSE A THREAT FOR DAMAGING WIND GUSTS/LARGE HAIL AND A FEW
   TORNADOES.
   
   ..GARNER.. 04/27/2011
   
   
   ATTN...WFO...BGM...BUF...CTP...LWX...PBZ...RLX...CLE...
   
   LAT...LON   42767911 42807768 41977693 40177738 38547985 38948145
               40938165 42108066 42767911