TORNADO WATCH NUMBER 332

   SEL2          URGENT - IMMEDIATE BROADCAST REQUESTED     TORNADO WATCH NUMBER 332     NWS STORM PREDICTION CENTER NORMAN OK     130 PM EDT FRI JUN 1 2012          THE NWS STORM PREDICTION CENTER HAS ISSUED A     TORNADO WATCH FOR PORTIONS OF                  MARYLAND            NORTHWEST NORTH CAROLINA            SOUTH-CENTRAL PENNSYLVANIA            WESTERN AND NORTHERN VIRGINIA            EASTERN WEST VIRGINIA PANHANDLE          EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 900     PM EDT.          TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND     GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE     AREAS.          THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE     MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF ALTOONA     PENNSYLVANIA TO 40 MILES WEST OF GREENSBORO NORTH CAROLINA.  FOR     A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH     OUTLINE UPDATE (WOUS64 KWNS WOU2).          REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR     TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH     AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR     THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS     AND POSSIBLE WARNINGS.          DISCUSSION...STRONG FORCED ASCENT WITH A LARGE SCALE TROUGH WAS     LIKELY CONTRIBUTING TO AN INCREASE IN LOW-TOPPED CONVECTION ALONG A      COLD FRONT NOW SITUATED FROM ERN OH SWD ACROSS WV...EXTREME SWRN VA     AND ERN TN. EXPECT THAT THIS CONVECTION WILL CROSS THE SPINE OF THE     APPALACHIANS OVER THE NEXT 2 HOURS. AS THE FRONT BEGINS TO INTERACT     WITH GREATER INSTABILITY EAST OF THE MOUNTAINS...MORE  VIGOROUS     STORM DEVELOPMENT IN THE FORM OF BOWING/LEWPING LINE SEGMENTS CAN BE     EXPECTED. A WEAK FRONTAL WAVE MAY ALSO TAKE FORM WITH TIME     COINCIDENT WITH AN INCREASE IN STORMS ALONG A WARM FRONT EXTENDING     ACROSS SRN PA AND INTO THE DELMARVA REGION. IN ADDITION TO WIND     DAMAGE AND SOME HAIL THREAT WITH THE STORMS ALONG THE ADVANCING     FRONT...AN ENHANCED BUT FOCUSED TORNADO THREAT MAY EVOLVE NEAR THE     FRONTAL WAVE AND WARM FRONT.          AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL     SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE     WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO     450. MEAN STORM MOTION VECTOR 22035.