SEL0
   
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 150
NWS STORM PREDICTION CENTER NORMAN OK
1205 PM EDT SAT APR 16 2011
   
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 
   
       CENTRAL AND EASTERN NORTH CAROLINA
       CENTRAL AND EASTERN SOUTH CAROLINA
       SOUTHERN VIRGINIA
       COASTAL WATERS
   
EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 1205 PM UNTIL
900 PM 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 95 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES SOUTH SOUTHEAST OF
CHARLESTON SOUTH CAROLINA TO 60 MILES NORTH NORTHEAST OF SOUTH
HILL VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).
   
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 149...
   
DISCUSSION...TSTMS WILL CONTINUE TO INTENSIFY TODAY ALONG AND AHEAD
OF COLD FRONT...AND THE S OF WARM FRONT RETREATING NWD THROUGH NC
INTO VA.  AMBIENT WARM SECTOR IS MOIST AND BREAKS IN THE CLOUDS WILL
SUPPORT LOCALLY STRONG DIABATIC HEATING WITH MLCAPE VALUES
INCREASING TO 1000-1500 J/KG.  THIS INSTABILITY COUPLED WITH
EFFECTIVE BULK SHEAR OF 50-60 KT...EFFECTIVE SRH VALUES OF 300-450+
M2/S2 AND ANTICIPATED DISCRETE STORM MODES SUGGESTS A HIGH
LIKELIHOOD OF LONG-LIVED SUPERCELLS CAPABLE OF SIGNIFICANT
TORNADOES.
   
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
450. MEAN STORM MOTION VECTOR 24040.
   
   
...MEAD