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WWUS20 KWNS 130139

SEL9

SPC WW 130139

COZ000-KSZ000-NEZ000-130900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 159

NWS STORM PREDICTION CENTER NORMAN OK

740 PM MDT THU APR 12 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EAST-CENTRAL COLORADO

       NORTHWEST KANSAS

       SOUTHWEST NEBRASKA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 740 PM

UNTIL 300 AM MDT.



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 EAST AND WEST OF A LINE FROM 10 MILES NORTH

NORTHEAST OF MCCOOK NEBRASKA TO 80 MILES SOUTH SOUTHEAST OF

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 157...WW 158...



DISCUSSION...TSTMS WILL LIKELY PERSIST TONIGHT ALONG COLD FRONT AS

IT PROGRESSES EWD/SEWD...OVERTAKING DRYLINE.  00Z SOUNDINGS INDICATE

THAT MARGINAL BOUNDARY LAYER MOISTURE AND PERSISTENT CLOUD COVER

HAVE LIMITED THE DEGREE OF DESTABILIZATION...AND THE ONSET OF

DIABATIC COOLING IN THE BOUNDARY LAYER WILL RESULT IN ACCUMULATING

CONVECTIVE INHIBITION.  WHILE A TORNADO IS POSSIBLE OWING TO THE

PRESENCE OF STRONG LOW-LEVEL SHEAR...THE INCREASING CONVECTIVE

INHIBITION AND LINEAR FORCING ALONG THE COLD FRONT ARE EXPECTED TO

MITIGATE THIS THREAT WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY

HAZARDS.



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 22025.





...MEAD

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