Tornado Watch 637

Issued

Sep 8, 2012, 12:40 PM EDT (16:40 UTC)

Expired

Sep 8, 2012, 7:18 PM EDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

1 in

Strongest gust expected

70 kt

The Albany radar (KENX), 60 km from the middle of the area, began a volume at 16:42 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

60%

One or more EF2 to EF5 tornadoes

30%

Ten or more severe wind reports

95%

One or more gusts of 65 knots or more

70%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 1926Sep 8, 8:42 AM EDT
• Mesoscale Discussion 1927Sep 8, 10:39 AM EDT
• Mesoscale Discussion 1928Sep 8, 11:38 AM EDT
• Mesoscale Discussion 1931Sep 8, 1:30 PM EDT
• Mesoscale Discussion 1934Sep 8, 2:46 PM EDT
• Mesoscale Discussion 1936Sep 8, 3:55 PM EDT
• Mesoscale Discussion 1939Sep 8, 6:17 PM EDT

917 
WWUS20 KWNS 081642
SEL7
SPC WW 081642
CTZ000-MAZ000-NYZ000-PAZ000-VTZ000-090200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 637
NWS STORM PREDICTION CENTER NORMAN OK
1240 PM EDT SAT SEP 8 2012

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

       EXTREME NORTHWESTERN CONNECTICUT
       EXTREME WESTERN MASSACHUSETTS
       CENTRAL AND EASTERN NEW YORK
       NORTHEAST PENNSYLVANIA
       VERMONT

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 1240 PM UNTIL
1000 PM EDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES SOUTHWEST OF
MONTICELLO NEW YORK TO 40 MILES NORTH OF BURLINGTON VERMONT.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU7).

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 634...WW 635...WW 636...

DISCUSSION...A SQUALL LINE ALONG THE SURFACE COLD FRONT...AS WELL AS
OTHER STORMS IN ALONG A PRE-FRONTAL DIFFERENTIAL HEATING ZONE...WILL
INTENSIFY THROUGH THE AFTERNOON AS THE FRONT APPROACHES AN AREA OF
GREATER MOISTURE/INSTABILITY.  MEANWHILE...VERTICAL SHEAR PROFILES
WILL CONTINUE TO STRENGTHEN THROUGH THE AFTERNOON AS STRONG MIDLEVEL
TROUGH EJECTS NEWD FROM THE UPPER OH VALLEY.  THE NET RESULT WILL BE
AN ENVIRONMENT FAVORABLE FOR WIDESPREAD DAMAGING WINDS AND EMBEDDED
TORNADIC CIRCULATIONS WITHIN THE FRONTAL SQUALL LINE...AS WELL AS
MORE DISCRETE SUPERCELLS WITH AN ASSOCIATED TORNADO RISK ALONG A
PRE-FRONTAL CONFLUENCE BAND ACROSS SE NY/WRN MA/WRN CT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 25045.


...THOMPSON

Tornado Watches in New York, 2012Tornado Watches in Vermont, 2012Tornado Watches in Pennsylvania, 2012Every tornado watch in 2012

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.