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352 

WWUS20 KWNS 120101

SEL4

SPC WW 120101

DEZ000-MDZ000-NJZ000-CWZ000-120400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 634

NWS STORM PREDICTION CENTER NORMAN OK

905 PM EDT MON JUL 11 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DELAWARE

       EASTERN MARYLAND

       SOUTHERN NEW JERSEY

       COASTAL WATERS



EFFECTIVE THIS MONDAY NIGHT FROM 905 PM UNTIL MIDNIGHT 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 40

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

NORTHEAST OF WILMINGTON DELAWARE TO 55 MILES SOUTH OF DOVER

DELAWARE.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 629...WW 631...WW

632...WW 633...



DISCUSSION...BAND OF TSTMS WITH A HISTORY OF DAMAGING WINDS IS

EXPECTED TO CONTINUE EWD ACROSS THE WATCH AREA LATE THIS EVENING.

00Z IAD SOUNDING IS LIKELY QUITE REPRESENTATIVE OF THE INFLOW AIR

MASS WITH A MOIST AND HOT BOUNDARY LAYER AND STEEP LOW-LEVEL LAPSE

RATES CONTRIBUTING TO MLCAPE OF AROUND 3000 J/KG.  DESPITE THE ONSET

OF NOCTURNAL COOLING...THE PRESENCE OF THE STRONG INSTABILITY WILL

BE SUFFICIENT TO MAINTAIN ROBUST UPDRAFTS AND A CONTINUED THREAT FOR

SOME HAIL AND DAMAGING WINDS.



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 27030.





...MEAD

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