

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

