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090 

WWUS20 KWNS 280018

SEL4

SPC WW 280018

DEZ000-MDZ000-NJZ000-NYZ000-PAZ000-CWZ000-280800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 244

NWS STORM PREDICTION CENTER NORMAN OK

815 PM EDT WED APR 27 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DELAWARE

       EASTERN MARYLAND

       NORTHERN NEW JERSEY

       EASTERN NEW YORK

       EASTERN PENNSYLVANIA

       COASTAL WATERS



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 815 PM

UNTIL 400 AM 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 55

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES EAST

NORTHEAST OF MASSENA NEW YORK TO 45 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 235...WW 236...WW

237...WW 238...WW 239...WW 240...WW 241...WW 242...WW 243...



DISCUSSION...BROKEN BAND OF TSTMS OVER CNTRL PARTS OF NY/PA IS

EXPECTED TO CONTINUE EWD INTO THE HUDSON/DE RIVER VALLEYS WHERE

BOUNDARY LAYER IS COMPARATIVELY MORE MOIST WITH DEWPOINTS IN THE

60S.  00Z IAD/ALB SOUNDINGS INDICATE THAT MLCAPE VALUES RANGE FROM

AROUND 500 J/KG ACROSS NRN PORTIONS OF WW AREA...TO 1000-1200 J/KG

OVER THE SOUTH.  VERTICAL SHEAR WILL STRENGTHEN TONIGHT IN ADVANCE

OF UPSTREAM SYSTEM OVER THE OH VALLEY WITH ENVIRONMENT REMAINING

SUPPORTIVE OF BOWING AND SUPERCELL TYPE STRUCTURES.  WHILE A BRIEF

TORNADO IS POSSIBLE...DAMAGING WINDS AND HAIL APPEAR TO BE THE

PRIMARY SEVERE WEATHER HAZARDS.



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 400. MEAN STORM

MOTION VECTOR 24040.





...MEAD

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