SEL1 URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 241 NWS STORM PREDICTION CENTER NORMAN OK 650 PM EDT WED APR 27 2011 THE NWS STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF EASTERN ALABAMA NORTHERN AND CENTRAL GEORGIA WESTERN NORTH CAROLINA UPSTATE SOUTH CAROLINA EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 650 PM UNTIL 200 AM EDT. ...THIS IS A PARTICULARLY DANGEROUS SITUATION... DESTRUCTIVE TORNADOES...LARGE HAIL TO 2 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 90 STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHWEST OF HICKORY NORTH CAROLINA TO 35 MILES EAST SOUTHEAST OF MONTGOMERY ALABAMA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1). 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. OTHER WATCH INFORMATION...CONTINUE...WW 232...WW 234...WW 235...WW 236...WW 237...WW 238...WW 239...WW 240... DISCUSSION...LONG-LIVED SUPERCELLS WITH A HISTORY OF DESTRUCTIVE TORNADOES OVER PORTIONS OF ERN TN AND AL ARE EXPECTED TO RAPIDLY MOVE EWD INTO THE WW AREA THIS EVENING. EWD MIGRATION OF 50-60+ KT LLJ AXIS WILL SUPPORT CONTINUED AIR MASS DESTABILIZATION WITH MLCAPE VALUES REMAINING IN THE 1000-2000 J/KG RANGE. WHEN COUPLED WITH 50-70 KT EFFECTIVE BULK SHEAR AND STEADILY STRENGTHENING LOW-LEVEL SHEAR...SETUP WILL REMAIN QUITE SUPPORTIVE OF SIGNIFICANT TORNADOES...SOME OF WHICH COULD BE LONG-TRACKED. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 24045. ...MEAD |