MESOSCALE DISCUSSION 0104
   NWS STORM PREDICTION CENTER NORMAN OK
   0432 PM CST WED FEB 11 2009
   
   AREAS AFFECTED...SE OH...SW PA...WV...WRN MD...WRN VA
   
   CONCERNING...TORNADO WATCH 18...
   
   VALID 112232Z - 120000Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 18 CONTINUES.
   
   A WELL-DEVELOPED SQUALL-LINE FROM SRN OH SWD INTO FAR WRN KY WILL
   CONTINUE MOVING ENEWD ACROSS WV...ERN OH AND WRN VA LATE THIS
   AFTERNOON. A WIND DAMAGE THREAT SHOULD CONTINUE WITH THE
   SQUALL-LINE. THE LINE SHOULD EXIT THE SRN PART OF TORNADO WATCH 18
   IN ABOUT 1 HOUR. THEREFORE...A SEVERE WATCH WILL BE NEEDED EAST OF
   WW 18.
   
   WATER VAPOR IMAGERY SHOWS A NEGATIVELY TILTED UPPER-LEVEL TROUGH AND
   LOW OVER THE OH VALLEY WITH A DRY SLOT PRESENT WRAPPING AROUND THE
   ERN SIDE OF THE SYSTEM ACROSS CNTRL KY AND ERN IND. AHEAD OF THIS
   FEATURE...A FINE LINE OF SEVERE CONVECTION IS PRESENT JUST AHEAD OF
   A POWERFUL 115 KT MID-LEVEL JET. THE STRONG VERTICAL SHEAR
   ASSOCIATED WITH THE JET AND VERY FOCUSED LARGE-SCALE ASCENT EAST OF
   THE DRY SLOT IS SUPPORTING THE SQUALL-LINE. THE SQUALL-LINE IS
   MOVING ABOUT 60 KT AND THIS SHOULD BE SUFFICIENT FOR WIND DAMAGE.
   THE SQUALL-LINE SHOULD REACH THE MID-ATLANTIC BY EARLY EVENING
   THEREFORE...THE NEW SEVERE THUNDERSTORM WATCH WILL NEED TO INCLUDE
   SW PA...WRN MD AND WRN VA.
   
   ..BROYLES.. 02/11/2009
   
   
   ATTN...WFO...AKQ...CTP...LWX...RNK...PBZ...RLX...CLE...MRX...
   JKL...ILN...
   
   LAT...LON   36707942 36568060 36658174 36888222 37738215 38698223
               39728274 40148281 40528204 40778047 40847931 40577806
               40167767 39127773 37507783 36977844 36707942