

248 

WWUS20 KWNS 181717

SEL5

SPC WW 181717

NYZ000-182300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 645

NWS STORM PREDICTION CENTER NORMAN OK

120 PM EDT TUE SEP 18 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTH-CENTRAL NEW YORK



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 120 PM UNTIL

700 PM EDT.



TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE

MILES EAST AND WEST OF A LINE FROM 10 MILES WEST NORTHWEST OF

UTICA NEW YORK TO 20 MILES SOUTHEAST OF BINGHAMTON NEW YORK.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 641...WW 642...WW

643...WW 644...



DISCUSSION...A FORCED CONVECTIVE BAND OVER S-CNTRL NY IS EXPECTED TO

INTENSIFY AND GRADUAL DEVELOP NWD WHILE AT THE SAME TIME ADVANCING

EWD.  AMBIENT ENVIRONMENT IS ONLY MARGINALLY UNSTABLE BUT STRONGLY

SHEARED AND FORCED WHICH WILL PROMOTE EMBEDDED LEWP STRUCTURES AND

MESOVORTICES CAPABLE OF DAMAGING WINDS AND POSSIBLY TORNADOES.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

350. MEAN STORM MOTION VECTOR 23040.





...MEAD

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