

303 

WWUS20 KWNS 112156

SEL1

SPC WW 112156

COZ000-KSZ000-NEZ000-WYZ000-120500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 571

NWS STORM PREDICTION CENTER NORMAN OK

455 PM CDT SAT JUL 11 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST COLORADO

       NORTHWEST KANSAS

       WESTERN NEBRASKA PANHANDLE

       SOUTHEAST WYOMING



EFFECTIVE THIS SATURDAY AFTERNOON FROM 455 PM UNTIL MIDNIGHT CDT.



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 55 MILES NORTH OF

TORRINGTON WYOMING TO 50 MILES SOUTHWEST OF BURLINGTON COLORADO.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 570...



DISCUSSION...SCATTERED THUNDERSTORMS ARE EXPECTED TO CONTINUE TO

INTENSIFY OVER THE FOOTHILLS OF CENTRAL CO AND SOUTHEAST WY...AND

SPREAD EASTWARD INTO THE PLAINS THIS EVENING.  EFFECTIVE SHEAR

VALUES ARE SUFFICIENT FOR SUPERCELLS...WHILE DEWPOINTS IN THE 60S

AND STRONG HEATING ARE YIELDING MLCAPE VALUES OF 2000-3000 J/KG.

LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE IN STRONGER STORMS

THROUGH THE EVENING.



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 30025.





...HART

