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348 

WWUS20 KWNS 290212

SEL1

SPC WW 290212

KSZ000-OKZ000-290700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 41

NWS STORM PREDICTION CENTER NORMAN OK

810 PM CST TUE FEB 28 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EASTERN KANSAS

       NORTH CENTRAL AND NORTHEAST OKLAHOMA



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 810 PM

UNTIL 100 AM CST.



TORNADOES...HAIL TO 1.5 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 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH NORTHWEST OF

TOPEKA KANSAS TO 15 MILES SOUTHEAST OF CHANDLER OKLAHOMA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU1).



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...THIS TORNADO WATCH REPLACES TORNADO

WATCH NUMBER 40. WATCH NUMBER 40 WILL NOT BE IN EFFECT AFTER 810

PM CST. CONTINUE...WW 39...



DISCUSSION...THE EARLIER DRYLINE SUPERCELLS IN S CENTRAL KS ARE NOW

APPROACHING NE KS...AND MAY PERSIST FOR ANOTHER COUPLE OF HOURS AS

THE LOW LEVELS MOISTEN FROM S TO N.  FARTHER W/SW...CONVECTION

CONTINUES TO INCREASE/BACKBUILD AS THE COLD FRONT OVERTAKES THE

DRYLINE AND THE MIDLEVEL TROUGH EJECTS ENEWD OVER KS.  ADDITIONAL

LOW-LEVEL MOISTENING ACROSS OK/SE KS WILL SUPPORT CONVECTION ROOTED

AT OR VERY NEAR THE SURFACE...IN AN ENVIRONMENT WITH EFFECTIVE SRH

OF 400-700 M2/S2.  THE QUASI-LINEAR CONVECTIVE MODE AND MODEST

INSTABILITY SUGGEST THAT THE HAIL RISK WILL BE TEMPERED

SOMEWHAT...BUT SEMI-DISCRETE CELLS IN THE LINE WILL POSE A RISK FOR

DAMAGING GUSTS AND PERHAPS A COUPLE OF TORNADOES.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

450. MEAN STORM MOTION VECTOR 27040.





...THOMPSON

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