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000 

WWUS20 KWNS 210142

SEL3

SPC WW 210142

NEZ000-210700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 153

NWS STORM PREDICTION CENTER NORMAN OK

840 PM CDT FRI APR 20 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST AND CENTRAL NEBRASKA



EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 840 PM

UNTIL 200 AM 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH

NORTHEAST OF AINSWORTH NEBRASKA TO 50 MILES SOUTH OF NORTH PLATTE

NEBRASKA.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 152...



DISCUSSION...ONGOING CLUSTER OF STRONG/SEVERE THUNDERSTORMS OVER

SWRN NEB WILL CONTINUE TO EXPAND/DEVELOP NNEWD ALONG NOSE OF

INCREASING SLY LLJ THIS EVENING.  ENVIRONMENT IS CHARACTERIZED BY

VERY STEEP MID LEVEL LAPSE RATES...MODERATE MUCAPE AND MARGINALLY

SUFFICIENT DEEP SHEAR FOR SUPERCELLS.  THIS SUPPORTS A CONTINUED

THREAT OF LARGE HAIL AND POSSIBLY AND ISOLATED STRONG/SEVERE WIND

GUST WITH STRONGER...ELEVATED CORES TONIGHT.



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 20025.





...EVANS

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