Severe Thunderstorm Watch 263

Issued

May 3, 2011, 3:47 PM EDT (19:47 UTC)

Expired

May 3, 2011, 10:00 PM EDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The State College radar (KCCX), 85 km from the middle of the area, began a volume at 19:49 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

2%

Ten or more severe wind reports

50%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 692May 3, 2:27 PM EDT
• Mesoscale Discussion 694May 3, 6:51 PM EDT

017 
WWUS20 KWNS 031948
SEL3
SPC WW 031948
MDZ000-PAZ000-VAZ000-WVZ000-040200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 263
NWS STORM PREDICTION CENTER NORMAN OK
350 PM EDT TUE MAY 3 2011

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

       PARTS OF WESTERN MARYLAND
       LARGE PART OF CENTRAL AND EASTERN PENNSYLVANIA
       SMALL PART OF NORTHERN VIRGINIA
       SMALL PART OF EASTERN WEST VIRGINIA PANHANDLE

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 350 PM UNTIL
1000 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 70
STATUTE MILES EAST AND WEST OF A LINE FROM 10 MILES SOUTH OF
MARTINSBURG WEST VIRGINIA TO 45 MILES NORTH OF WILKESBARRE
PENNSYLVANIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).

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 EXPECTED TO INCREASE IN NUMBER AND
INTENSITY AHEAD OF COLD FRONT AND APPROACHING SURFACE LOW.  WITH
STRONG HEATING...MLCAPES ACROSS THE WATCH RANGE UPWARDS TO 1500
J/KG...WHICH COUPLED WITH 40-50KT OF SHEAR WILL SUPPORT A FEW
THUNDERSTORMS BECOMING SEVERE WITH DAMAGING WINDS THE PRIMARY
THREAT.

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 500. MEAN STORM
MOTION VECTOR 23035.


...HALES

Severe Thunderstorm Watches in Pennsylvania, 2011Severe Thunderstorm Watches in West Virginia, 2011Severe Thunderstorm Watches in Maryland, 2011Every severe thunderstorm watch in 2011

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.