

505 

WWUS20 KWNS 281809

SEL7

SPC WW 281809

DCZ000-DEZ000-MDZ000-NJZ000-PAZ000-VAZ000-CWZ000-290100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 387

NWS STORM PREDICTION CENTER NORMAN OK

210 PM EDT FRI JUN 28 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  DISTRICT OF COLUMBIA

  DELAWARE

  CENTRAL AND EASTERN MARYLAND

  CENTRAL AND SOUTHERN NEW JERSEY

  SOUTHEAST PENNSYLVANIA

  NORTHEAST VIRGINIA

  COASTAL WATERS



* EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 210 PM UNTIL

  900 PM EDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75

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

SOUTHEAST OF WASHINGTON DISTRICT OF COLUM TO 15 MILES NORTH OF

TRENTON NEW JERSEY.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 385...WW 386...



DISCUSSION...A FURTHER INCREASE IN TSTM COVERAGE IS ANTICIPATED THIS

AFTERNOON ALONG A DEVELOPING LEE TROUGH WERE THE ENVIRONMENT HAS

BECOME UNCAPPED WITH MLCAPE APPROACHING 2000 J/KG.  CURRENT VAD DATA

INDICATE THAT 50 KT WLY WINDS HAVE OVERSPREAD THE REGION AT 6 KM AGL

WHICH IS RESULTING IN SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS AND

BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND PERHAPS SOME HAIL.



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 27030.





...MEAD

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