

000 

WWUS20 KWNS 170308

SEL1

SPC WW 170308

DCZ000-DEZ000-MDZ000-VAZ000-WVZ000-CWZ000-171000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 611

NWS STORM PREDICTION CENTER NORMAN OK

1105 PM EDT THU AUG 16 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       DELAWARE

       MUCH OF MARYLAND

       NORTHERN AND EASTERN VIRGINIA

       THE EASTERN WEST VIRGINIA PANHANDLE

       COASTAL WATERS



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1105 PM

UNTIL 600 AM EDT.



HAIL TO 1 INCH 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 85

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH

NORTHEAST OF MARTINSBURG WEST VIRGINIA TO 35 MILES SOUTH OF

WALLOPS VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

SEVERE THUNDERSTORM WATCH NUMBER 606. WATCH NUMBER 606 WILL NOT

BE IN EFFECT AFTER 1105 PM EDT.



DISCUSSION...SCTD CLUSTERS OF MULTICELL TSTMS WITH THE POTENTIAL FOR

ISOLD WET MICROBURSTS EXPECTED TO PERSIST THROUGH EARLY FRIDAY AS WV

MCV CONTINUES EWD IN RELATIVELY FAST WLY FLOW ON SRN SIDE OF

AMPLIFYING ONTARIO TROUGH.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 28025.





...CORFIDI

