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WWUS20 KWNS 222027

SEL8

SPC WW 222027

NEZ000-WYZ000-230300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 338

NWS STORM PREDICTION CENTER NORMAN OK

220 PM MDT THU MAY 22 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PORTIONS OF WESTERN AND NORTHERN NEBRASKA

       SOUTHEASTERN WYOMING



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 220 PM UNTIL

900 PM MDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 60

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 65 MILES WEST

NORTHWEST OF TORRINGTON WYOMING TO 30 MILES EAST OF MULLEN

NEBRASKA.  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 334...WW 335...WW

336...WW 337...



DISCUSSION...SUPERCELLS IN NERN CO AND NRN KS ARE EXPECTED TO TRACK

NWD INTO SERN WY AND NRN/WRN NEB INTO THE EVENING HOURS. THESE

STORMS WILL MOVE OVER A COOL AND STABLE BOUNDARY LAYER...BUT

MODERATE ELEVATED INSTABILITY AND STRONG FORCING...ASSOCIATED WITH

SHORTWAVE TROUGH APPROACHING FROM CO...WILL BE FAVORABLE FOR

SUPERCELLS WITH SEVERE HAIL.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 18035.





...IMY

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