

000 

WWUS20 KWNS 212051

SEL2

SPC WW 212051

COZ000-KSZ000-NEZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 632

NWS STORM PREDICTION CENTER NORMAN OK

350 PM CDT TUE AUG 21 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FAR EAST CENTRAL COLORADO

       NORTHWESTERN KANSAS

       SOUTHWEST INTO CENTRAL NEBRASKA



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 350 PM UNTIL

1000 PM CDT.



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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES SOUTH OF

GOODLAND KANSAS TO 45 MILES NORTH NORTHWEST OF GRAND ISLAND

NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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 629...WW 630...WW 631...



DISCUSSION...STRONG HEATING AND INCREASED CONVERGENCE INVOF SURFACE

TROUGH/DRY LINE WILL CONTINUE TO FOSTER THUNDERSTORM DEVELOPMENT

THIS AFTERNOON/EARLY THIS EVENING.  EXTREMELY UNSTABLE AIR MASS AND

MODEST DEEP LAYER SHEAR SHOULD SUPPORT SEVERE THUNDERSTORMS CAPABLE

OF DAMAGING WINDS AND ISOLATED LARGE HAIL.



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 500. MEAN STORM

MOTION VECTOR 27015.





...EVANS

