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242 

WWUS20 KWNS 142043

SEL3

SPC WW 142043

COZ000-KSZ000-NEZ000-WYZ000-150300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 643

NWS STORM PREDICTION CENTER NORMAN OK

240 PM MDT THU JUL 14 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEASTERN COLORADO

       NORTHWESTERN KANSAS

       WESTERN NEBRASKA

       SOUTHEASTERN WYOMING



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 240 PM UNTIL

900 PM 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 95

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES EAST

NORTHEAST OF SCOTTSBLUFF NEBRASKA TO 20 MILES SOUTHEAST OF LIMON

COLORADO.  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 642...



DISCUSSION...VERY MOIST BOUNDARY LAYER CONDITIONS AND ADDITIONAL

HEATING WILL BE FAVORABLE FOR THUNDERSTORMS OVER NERN CO/SERN WY

HIGHER TERRAIN TO PROGRESS NEWD INTO THE PLAINS THROUGH THE EVENING

HOURS. DEEP LAYER SHEAR IS FAVORABLE FOR MULTICELL STORMS WITH

SEVERE HAIL. THE WIND DAMAGE THREAT MAY INCREASE LATER THIS EVENING

ACROSS THE EASTERN PORTIONS OF THE WATCH AS STRENGTHENING LOW LEVEL

JET MAY RESULT IN STORMS CONGEALING INTO A LINEAR MCS.



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 550. MEAN STORM

MOTION VECTOR 23020.





...IMY

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