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000 

WWUS20 KWNS 161800

SEL3

SPC WW 161800

DCZ000-DEZ000-MDZ000-NJZ000-VAZ000-WVZ000-CWZ000-170100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 523

NWS STORM PREDICTION CENTER NORMAN OK

200 PM EDT MON JUL 16 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       DELAWARE

       NORTHERN AND EASTERN MARYLAND

       SOUTHERN NEW JERSEY

       VIRGINIA

       EXTREME EASTERN PANHANDLE OF WEST VIRGINIA

       COASTAL WATERS



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 200 PM UNTIL 900

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 80

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

BALTIMORE MARYLAND TO 50 MILES SOUTH OF LYNCHBURG VIRGINIA.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU3).



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.



DISCUSSION...THUNDERSTORMS ARE INCREASING ALONG THE ERN SLOPES OF

THE MOUNTAINS AS DIURNAL HEATING IS ALLOWING LIFTED PARCELS TO REACH

THE LFC.  STORMS WILL BE MOVING INTO AN INCREASINGLY MOIST AND

UNSTABLE ENVIRONMENT WITH MLCAPE OF 1000-1500 J/KG.  VAD PROFILES

AND HOURLY RUC ANALYSES INDICATE 30-35 KT WESTERLY MID LEVEL WINDS

ACROSS THE REGION WHICH ARE CONTRIBUTING TO DEEP LAYER SHEAR OF

30-35 KT.  THIS  WILL PROMOTE ORGANIZED CONVECTIVE BANDS AND ENHANCE

POTENTIAL FOR SEVERE THUNDERSTORMS TO DEVELOP.



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 26025.





...WEISS

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