Post by Nws Olney Maryland on Apr 27, 2011 17:48:10 GMT -5
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 240
NWS STORM PREDICTION CENTER OLNEY MD
615 PM EDT WED APR 27 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
DISTRICT OF COLUMBIA
MARYLAND
NORTHERN NORTH CAROLINA
CENTRAL AND EASTERN VIRGINIA
EASTERN WEST VIRGINIA
COASTAL WATERS
EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 615 PM
UNTIL 200 AM EDT.
TORNADOES...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 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES NORTHEAST OF
MARTINSBURG WEST VIRGINIA TO 30 MILES WEST SOUTHWEST OF RALEIGH
NORTH CAROLINA. 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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 233. WATCH NUMBER 233 WILL NOT BE IN EFFECT AFTER
615 PM EDT. CONTINUE...WW 232...WW 234...WW 235...WW 236...WW
237...WW 238...WW 239...
DISCUSSION...TSTMS HAVE RAPIDLY INTENSIFIED THIS EVENING WITHIN A
MOIST AND MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE VALUES OF
1000-2000 J/KG. DEEP-LAYER VERTICAL SHEAR IS ALREADY SUPPORTIVE OF
SUPERCELLS...AND LOW-LEVEL SHEAR IS FORECAST TO STRENGTHEN THROUGH
THE REMAINDER OF THE EVENING WITH EFFECTIVE SRH VALUES APPROACHING
250-300 M2/S2. AS SUCH...THE POTENTIAL FOR TORNADOES WILL EXIST IN
ADDITION TO DAMAGING WINDS AND HAIL.
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 24035.
MILLER
TORNADO WATCH NUMBER 240
NWS STORM PREDICTION CENTER OLNEY MD
615 PM EDT WED APR 27 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
DISTRICT OF COLUMBIA
MARYLAND
NORTHERN NORTH CAROLINA
CENTRAL AND EASTERN VIRGINIA
EASTERN WEST VIRGINIA
COASTAL WATERS
EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 615 PM
UNTIL 200 AM EDT.
TORNADOES...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 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES NORTHEAST OF
MARTINSBURG WEST VIRGINIA TO 30 MILES WEST SOUTHWEST OF RALEIGH
NORTH CAROLINA. 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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 233. WATCH NUMBER 233 WILL NOT BE IN EFFECT AFTER
615 PM EDT. CONTINUE...WW 232...WW 234...WW 235...WW 236...WW
237...WW 238...WW 239...
DISCUSSION...TSTMS HAVE RAPIDLY INTENSIFIED THIS EVENING WITHIN A
MOIST AND MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE VALUES OF
1000-2000 J/KG. DEEP-LAYER VERTICAL SHEAR IS ALREADY SUPPORTIVE OF
SUPERCELLS...AND LOW-LEVEL SHEAR IS FORECAST TO STRENGTHEN THROUGH
THE REMAINDER OF THE EVENING WITH EFFECTIVE SRH VALUES APPROACHING
250-300 M2/S2. AS SUCH...THE POTENTIAL FOR TORNADOES WILL EXIST IN
ADDITION TO DAMAGING WINDS AND HAIL.
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 24035.
MILLER