

000 

WWUS20 KWNS 281808

SEL1

SPC WW 281808

DCZ000-DEZ000-MDZ000-NCZ000-NJZ000-PAZ000-VAZ000-WVZ000-CWZ000-29030

0-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 461

NWS STORM PREDICTION CENTER NORMAN OK

210 PM EDT THU JUN 28 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       DELAWARE

       MARYLAND

       NORTHERN NORTH CAROLINA

       NEW JERSEY

       SOUTHEAST PENNSYLVANIA

       VIRGINIA

       EASTERN WEST VIRGINIA

       COASTAL WATERS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 210 PM UNTIL

1100 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 100

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTHEAST

OF TRENTON NEW JERSEY TO 45 MILES SOUTH SOUTHWEST OF BLUEFIELD

WEST 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.



DISCUSSION...VERY WARM AND HUMID CONDITIONS HAVE DEVELOPED FROM

SOUTHWEST VA/NORTHWEST NC ACROSS THE DELMARVA REGION INTO NJ/PA.

SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP THROUGHOUT THIS

REGION THIS AFTERNOON AND EVENING WHERE MLCAPE VALUES WILL BE IN

EXCESS OF 2000 J/KG.  STEEP LOW LEVEL LAPSE RATES AND SUFFICIENT

VERTICAL SHEAR WILL ENHANCE THE RISK OF DAMAGING WINDS AND HAIL IN

STRONGER CELLS.



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 27020.





...HART

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