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105 

WWUS20 KWNS 222153

SEL9

SPC WW 222153

COZ000-NEZ000-WYZ000-230500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 419

NWS STORM PREDICTION CENTER NORMAN OK

350 PM MDT FRI JUN 22 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST COLORADO

       WESTERN NEBRASKA INCLUDING THE PANHANDLE

       EASTERN WYOMING



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 350 PM UNTIL

1100 PM MDT.



HAIL TO 2.5 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 35 MILES WEST

NORTHWEST OF CHADRON NEBRASKA TO 55 MILES SOUTHEAST OF AKRON

COLORADO.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 417...WW 418...



DISCUSSION...TSTM INITIATION HAS RECENTLY OCCURRED NEAR AKO WITH

ADDITIONAL DEVELOPMENT ANTICIPATED THIS AFTERNOON FARTHER N ALONG

LEE TROUGH INTO FAR ERN WY AND THE NEB PNHDL.  AMBIENT ENVIRONMENT

IS CHARACTERIZED BY STEEP LAPSE RATES AND A HOT BOUNDARY LAYER WITH

MLCAPE ESTIMATED UPWARDS OF 2000-3000 J/KG.  MOREOVER...EXPECT

MIDLEVEL WIND FIELD AND RESULTANT VERTICAL SHEAR TO STRENGTHEN INTO

THIS EVENING WITH APPROACH OF SHORTWAVE TROUGH THROUGH THE CNTRL

ROCKIES.  AS SUCH...THE SETUP WILL BECOME INCREASINGLY FAVORABLE FOR

SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WIND GUSTS.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 25020.





...MEAD

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