

759 

WWUS20 KWNS 291430

SEL2

SPC WW 291430

NYZ000-OHZ000-PAZ000-WVZ000-LEZ000-LOZ000-292300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 312

NWS STORM PREDICTION CENTER NORMAN OK

1030 AM EDT TUE MAY 29 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN NEW YORK

       EASTERN OHIO

       WESTERN AND CENTRAL PENNSYLVANIA

       NORTHERN WEST VIRGINIA

       LAKE ERIE

       LAKE ONTARIO



EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 1030 AM UNTIL 700

PM EDT.



HAIL TO 2 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 70

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH

NORTHWEST OF SYRACUSE NEW YORK TO 45 MILES EAST SOUTHEAST OF

ZANESVILLE OHIO.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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...STORMS ARE INCREASING OVER ERN OH IN ADVANCE OF AN

UPPER TROUGH MOVING TOWARD THE UPPER GREAT LAKES REGION.  12Z

SOUNDINGS AND LATEST SURFACE OBSERVATIONS INDICATE AN

MODERATELY/STRONGLY UNSTABLE AIR MASS IS DEVELOPING OVER PA AND NY

AS STRONG DIABATIC HEATING COMBINES WITH AMPLE MOISTURE AND MODERATE

STEEP LAPSE RATES BELOW 500 MB.  MULTIPLE BANDS OF STORMS ARE LIKELY

TO DEVELOP TODAY CAPABLE OF PRODUCING STRONG WIND GUSTS AND SEVERE

HAIL.

ADDITIONAL WATCHES WILL LIKELY BE NEEDED TO THE EAST OF THIS WATCH

BY THE EARLY AFTERNOON HOURS.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 24025.





...WEISS

