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711 

WWUS20 KWNS 212043

SEL8

SPC WW 212043

KSZ000-NEZ000-220400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 318

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT SAT MAY 21 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTH-CENTRAL AND NORTHEAST KANSAS

       CENTRAL NEBRASKA



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

1100 PM CDT.



HAIL TO 2 INCHES 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 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES EAST

NORTHEAST OF TOPEKA KANSAS TO 25 MILES NORTH NORTHWEST OF RUSSELL

KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 316...WW 317...



DISCUSSION...HIGH-BASED TSTMS ONGOING OVER CNTRL NEB INTO N-CNTRL KS

ARE EXPECTED TO INTENSIFY AS THEY ENCOUNTER AN INCREASING MOIST AND

UNSTABLE AIR MASS WHERE MLCAPE HAS INCREASED TO 2000-2500 J/KG.

ADDITIONAL STORM DEVELOPMENT WILL BE POSSIBLE LATE THIS AFTERNOON

FROM VICINITY OF SURFACE LOW NEAR SLN SWD ALONG DRYLINE AS CAP IS

GRADUALLY ERODED.  AREA PROFILER/VAD DATA SHOW VERTICALLY VEERING

WIND PROFILES WITH 35-40 KT OF DEEP-LAYER SHEAR WHICH WILL BE

SUPPORTIVE OF SUPERCELLS CAPABLE OF MAINLY LARGE HAIL AND DAMAGING

WIND GUSTS.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 26025.





...MEAD

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