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WWUS20 KWNS 302142

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COZ000-NEZ000-310300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 404

NWS STORM PREDICTION CENTER NORMAN OK

445 PM CDT MON MAY 30 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF NORTHEAST COLORADO

       PARTS OF WESTERN AND SOUTHWESTERN NEBRASKA



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 445 PM UNTIL

1000 PM CDT.



HAIL TO 1.5 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES EAST

SOUTHEAST OF AKRON COLORADO TO 10 MILES NORTH NORTHEAST OF

VALENTINE NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 402...WW 403...



DISCUSSION...STRONG FRONTAL PUSH ASSOCIATED WITH EJECTING UPPER

TROUGH EXPECTED TO DEVELOP STRONG/SEVERE THUNDERSTORMS ACROSS THE

WATCH.  WITH BRN SHEAR OF 60-70 KTS...STEEP MID LEVEL LAPSE RATES

AND MLCAPE AOA 1000 J/KG...DAMAGING WINDS EXPECTED TO BE THE PRIMARY

THREAT AS THUNDERSTORMS EVOLVE INTO A LINE.



AVIATION...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 500. MEAN STORM

MOTION VECTOR 23040.





...HALES

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