Severe Thunderstorm Watch 521

Issued

Jul 23, 2010, 12:46 PM EDT (16:46 UTC)

Expired

Jul 23, 2010, 8:00 PM EDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

1 in

Strongest gust expected

60 kt

The Buffalo radar (KBUF), 64 km from the middle of the area, began a volume at 16:47 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

10%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

10%

One or more hailstones of 2 inches or more

5%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1429Jul 23, 12:14 PM EDT
• Mesoscale Discussion 1436Jul 23, 6:23 PM EDT
• Mesoscale Discussion 1437Jul 23, 7:00 PM EDT

964 
WWUS20 KWNS 231646
SEL1
SPC WW 231646
NYZ000-OHZ000-PAZ000-LEZ000-240000-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 521
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM EDT FRI JUL 23 2010

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

       WESTERN NEW YORK
       PARTS OF NORTHEAST OHIO
       PARTS OF NORTHERN PENNSYLVANIA
       LAKE ERIE

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL
800 PM EDT.

HAIL TO 1 INCH 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 65
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES NORTHEAST
OF ITHACA NEW YORK TO 50 MILES NORTHWEST OF YOUNGSTOWN OHIO.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).

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...THUNDERSTORMS WILL INCREASE IN NUMBER AND INTENSITY
ACROSS THE WATCH AREA WHERE THE AIR MASS IS VERY MOIST...UNSTABLE
AND WITH LITTLE REMAINING CINH.  WITH 30-40 KT OF WLY FLOW WIND
DAMAGE WILL BECOME AN INCREASING THREAT AS THE STORMS DEVELOP.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION
VECTOR 26030.


...HALES

Severe Thunderstorm Watches in Pennsylvania, 2010Severe Thunderstorm Watches in New York, 2010Severe Thunderstorm Watches in Ohio, 2010Every severe thunderstorm watch in 2010

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.