

000 

WWUS20 KWNS 310807

SEL3

SPC WW 310807

IAZ000-NEZ000-311300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 143

NWS STORM PREDICTION CENTER NORMAN OK

310 AM CDT MON MAR 31 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME SOUTHWEST IOWA

       SOUTHEAST NEBRASKA



EFFECTIVE THIS MONDAY MORNING FROM 310 AM UNTIL 800 AM 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES WEST

NORTHWEST OF OMAHA NEBRASKA TO 20 MILES SOUTH OF BEATRICE

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 141...



DISCUSSION...CLUSTER OF ELEVATED THUNDERSTORMS WILL CONTINUE TO

SPREAD NWD/NEWD ON NOSE OF STRONG LLJ ACROSS OK/KS.  STEEP MID LEVEL

LAPSE RATES AND MOISTENING N OF THE WARM FRONT IN KS WILL RESULT IN

MUCAPE VALUES IN EXCESS OF 1500 J/KG...WHICH WILL SUPPORT STRONG

UPDRAFTS AND AN ATTENDANT HAIL THREAT.  ADDITIONALLY...EFFECTIVE

BULK SHEAR IN EXCESS OF 45 KT MAY ALSO SUPPORT A FEW ELEVATED

SUPERCELLS.



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 23035.





...THOMPSON

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