Tornado Watch 236

Issued

Apr 27, 2011, 3:10 PM EDT (19:10 UTC)

Expired

Apr 27, 2011, 10:00 PM EDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Buffalo radar (KBUF), 91 km from the middle of the area, began a volume at 19:11 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

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

40%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 624Apr 27, 1:24 PM EDT
• Mesoscale Discussion 638Apr 27, 6:50 PM EDT
• Mesoscale Discussion 643Apr 27, 9:03 PM EDT

924 
WWUS20 KWNS 271909
SEL6
SPC WW 271909
MDZ000-NYZ000-PAZ000-WVZ000-LEZ000-LOZ000-280200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 236
NWS STORM PREDICTION CENTER NORMAN OK
310 PM EDT WED APR 27 2011

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

       EXTREME WESTERN MARYLAND
       WESTERN NEW YORK
       WESTERN AND CENTRAL PENNSYLVANIA
       EXTREME NORTHERN WEST VIRGINIA
       LAKE ERIE
       LAKE ONTARIO

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 310 PM UNTIL
1000 PM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 100 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF ROCHESTER
NEW YORK TO 50 MILES SOUTH SOUTHWEST OF ALTOONA PENNSYLVANIA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).

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 231...WW 232...WW
233...WW 234...WW 235...

DISCUSSION...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP SOON
OVER WESTERN PA AND SPREAD EAST-NORTHEASTWARD ACROSS THE WATCH AREA
DURING THE LATE AFTERNOON AND EVENING.  MODERATE
INSTABILITY...COUPLED WITH STRONG VERTICAL SHEAR PROFILES WILL
PROMOTE ORGANIZED STORMS WITH SUPERCELLS/BOWS POSSIBLE.  LARGE HAIL
AND DAMAGING WINDS ARE THE MAIN THREAT.  HOWEVER...SUFFICIENT LOW
LEVEL SHEAR IS PRESENT FOR ISOLATED TORNADOES.

AVIATION...TORNADOES AND 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
450. MEAN STORM MOTION VECTOR 25040.


...HART

Tornado Watches in Pennsylvania, 2011Tornado Watches in New York, 2011Tornado Watches in West Virginia, 2011Every tornado 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.