

000 

WWUS20 KWNS 051700

SEL7

SPC WW 051700

NYZ000-PAZ000-LEZ000-060000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 487

NWS STORM PREDICTION CENTER NORMAN OK

100 PM EDT THU JUL 5 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN AND SOUTHERN NEW YORK

       NORTHERN PENNSYLVANIA

       LAKE ERIE



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 100 PM UNTIL

800 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 NORTH AND SOUTH OF A LINE FROM 50 MILES NORTH OF

MONTICELLO NEW YORK TO 35 MILES WEST NORTHWEST OF FRANKLIN

PENNSYLVANIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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.



DISCUSSION...TSTMS EXPECTED TO INCREASE OVER WRN NY AND PERHAPS NW

PA AHEAD OF UPR IMPULSE EMBEDDED IN MODERATE...DEEP WLY FLOW OVER

THE LWR GRT LKS.  HEATING AHEAD OF IMPULSE...WEAK UPSLOPE FLOW AND

CONVERGENCE ALONG LAKE/TERRAIN-INDUCED BOUNDARIES MAY ENHANCE CHANCE

FOR DAMAGING WINDS AND MARGINALLY SVR 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 450. MEAN STORM

MOTION VECTOR 29025.





...CORFIDI

