

385 

WWUS20 KWNS 221945

SEL3

SPC WW 221945

CTZ000-DEZ000-MDZ000-NJZ000-NYZ000-PAZ000-CWZ000-230300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 683

NWS STORM PREDICTION CENTER NORMAN OK

345 PM EDT WED SEP 22 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN CONNECTICUT

       DELAWARE

       EASTERN MARYLAND

       NEW JERSEY

       SOUTHEAST NEW YORK

       EASTERN PENNSYLVANIA

       COASTAL WATERS



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 345 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 55

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH

NORTHWEST OF POUGHKEEPSIE NEW YORK TO 40 MILES SOUTH OF DOVER

DELAWARE.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 680...WW 681...WW 682...



DISCUSSION...TSTMS ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON

ALONG/E OF LEE TROUGH AND SYNOPTIC COLD FRONT WITHIN A

WARM...MODERATELY UNSTABLE AIR MASS WITH SBCAPE VALUES OF 1000-2000

J/KG.  REGIONAL VWPS AND LATEST RUC OBJECTIVE FIELDS SUGGEST THAT

DEEP WLY WIND FIELD DECREASES WITH SWD EXTENT...THOUGH SUFFICIENT

VERTICAL SHEAR WILL EXIST ACROSS WW AREA TO SUPPORT ORGANIZE STORM

MODES INCLUDING SUPERCELL AND BOWING STRUCTURES WITH A RISK FOR

MAINLY DAMAGING WIND GUSTS.



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

