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