Severe Thunderstorm Watch 33

Issued

Feb 20, 2012, 2:50 PM CST (20:50 UTC)

Expired

Feb 20, 2012, 6:22 PM CST

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

1 in

Strongest gust expected

60 kt

The Vance AFB radar (KVNX), 58 km from the middle of the area, began a volume at 20:54 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

20%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

5%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 137Feb 20, 1:39 PM CST
• Mesoscale Discussion 138Feb 20, 4:50 PM CST
• Mesoscale Discussion 140Feb 20, 5:37 PM CST

017 
WWUS20 KWNS 202054
SEL3
SPC WW 202054
KSZ000-OKZ000-210400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 33
NWS STORM PREDICTION CENTER NORMAN OK
250 PM CST MON FEB 20 2012

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

       SOUTH-CENTRAL KANSAS
       CENTRAL OKLAHOMA

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 250 PM UNTIL
1000 PM CST.

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 60
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTHEAST OF
HUTCHINSON KANSAS TO 50 MILES SOUTHEAST OF CHICKASHA OKLAHOMA.
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...A CORRIDOR OF FOCUSED DCVA ATTENDANT TO POTENT MIDLEVEL
TROUGH WILL CONTINUE TO OVERSPREAD DRYLINE THIS
AFTERNOON...SUPPORTING A GRADUAL INCREASE IN STORM COVERAGE AND
INTENSITY.  THOUGH BOUNDARY LAYER MOISTURE REMAINS RATHER
LIMITED...CONSIDERABLE DYNAMIC COOLING IN THE MIDLEVELS IS YIELDING
A WEAKLY UNSTABLE ENVIRONMENT WITH SBCAPE VALUES AROUND 500 J/KG.
AREA VAD/PROFILER DATA ARE CURRENTLY EXHIBITING A VEER-BACK-VEER
SIGNATURE WHICH MAY INHIBIT THE EVOLUTION OF MORE ROBUST
SUPERCELL-TYPE STRUCTURES AND AN ATTENDANT TORNADO THREAT.
HOWEVER...SUFFICIENT VERTICAL SHEAR DOES EXIST FOR STORM
ORGANIZATION WITH ASSOCIATED RISKS FOR DAMAGING WIND GUSTS AND HAIL
GIVEN THE STRONG GRADIENT FLOW AND COLD THERMODYNAMIC
PROFILES...RESPECTIVELY.

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 300. MEAN STORM MOTION
VECTOR 25045.


...MEAD

Severe Thunderstorm Watches in Oklahoma, 2012Severe Thunderstorm Watches in Kansas, 2012Every severe thunderstorm 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.