Monday, July 9, 2007

WATCHES: Severe Thunderstorm Watch Number 499

WWUS20 KWNS 092045
SEL9
SPC WW 092045
NYZ000-VTZ000-100300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 499
NWS STORM PREDICTION CENTER NORMAN OK
440 PM EDT MON JUL 9 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

EXTREME NORTHERN NEW YORK
NORTHERN AND CENTRAL VERMONT

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 440 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 45
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES WEST OF
SARANAC LAKE NEW YORK TO 30 MILES EAST NORTHEAST OF MONTPELIER
VERMONT. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).

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...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 494. WATCH NUMBER 494 WILL NOT
BE IN EFFECT AFTER 440 PM EDT. CONTINUE...WW 495...WW 496...WW
497...WW 498...

DISCUSSION...TSTMS HAVE REDEVELOPED ACROSS REGION WITHIN
DESTABILIZING AIR MASS WITH MLCAPES OF 500-1500 J/KG. STRONGEST
VERTICAL SHEAR RESIDES NEAR AND E OF WARM FRONT ORIENTED IN N-S
FASHION ALONG THE HUDSON VALLEY. AS SUCH...POTENTIAL WILL EXIST FOR
SUPERCELLS AND/OR BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND
LARGE HAIL THROUGH THE EVENING HOURS. A BRIEF TORNADO IS POSSIBLE
WITH ANY MATURE STORMS CROSSING WARM FRONTAL BOUNDARY...THOUGH
HAIL/HIGH WINDS WILL REMAIN THE PRIMARY SEVERE THREATS.

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 450. MEAN STORM
MOTION VECTOR 28035.


..MEAD/THOMPSON

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