

815 

WWUS20 KWNS 221844

SEL2

SPC WW 221844

DCZ000-MDZ000-VAZ000-WVZ000-CWZ000-230200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 682

NWS STORM PREDICTION CENTER NORMAN OK

245 PM EDT WED SEP 22 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       MARYLAND

       NORTHERN VIRGINIA

       EASTERN WEST VIRGINIA PANHANDLE

       COASTAL WATERS



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 245 PM UNTIL

1000 PM EDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH

NORTHWEST OF BALTIMORE MARYLAND TO 20 MILES EAST SOUTHEAST OF

CHARLOTTESVILLE VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 680...WW 681...



DISCUSSION...TSTMS ARE EXPECTED TO INTENSIFY ALONG LEE TROUGH AND

MOVE INTO THE REGION FROM THE W/NW AS AIR MASS CONTINUES TO

WARM/DESTABILIZE.  WHILE AREA RESIDES ALONG SRN FRINGE OF

STRONGER...ZONAL MID AND HIGH-LEVEL WIND FIELD...SUFFICIENT VERTICAL

SHEAR WILL EXIST TO SUPPORT ORGANIZED STORMS INCLUDING MULTICELLS

AND BOWING LINE SEGMENTS WITH A RISK FOR DAMAGING WIND GUSTS.



AVIATION...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 500. MEAN STORM

MOTION VECTOR 27025.





...MEAD

