

268 

WWUS20 KWNS 101857

SEL6

SPC WW 101857

COZ000-KSZ000-NEZ000-110300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 446

NWS STORM PREDICTION CENTER NORMAN OK

155 PM CDT SAT JUL 10 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FAR NORTHEAST COLORADO

       NORTHWEST KANSAS

       MUCH OF WESTERN AND CENTRAL NEBRASKA



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 155 PM UNTIL

1000 PM 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 85

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES NORTHEAST OF

VALENTINE NEBRASKA TO 55 MILES SOUTH SOUTHEAST OF GOODLAND

KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



DISCUSSION...STRONG DAYTIME HEATING AND THE INCREASING INFLUENCE OF

MIDLEVEL TROUGH APPROACHING FROM THE W ARE EXPECTED TO FOSTER

ISOLATED TO SCATTERED TSTM DEVELOPMENT ALONG LEE TROUGH WITHIN THE

NEXT ONE TO TWO HOURS.  AMBIENT AIR MASS E OF LEE TROUGH IS ALREADY

MODERATELY UNSTABLE WITH MLCAPE OF 1000-2000 J/KG...WITH FURTHER

DESTABILIZATION ANTICIPATED THROUGH LATE AFTERNOON.  WHEN COUPLED

WITH STEADILY STRENGTHENING MID AND HIGH-LEVEL FLOW ATTENDANT TO

SHORT WAVE TROUGH...ENVIRONMENT WILL REMAIN SUPPORTIVE OF ORGANIZED

SEVERE STORMS INCLUDING SUPERCELLS WITH THE THREAT FOR 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 550. MEAN STORM

MOTION VECTOR 28020.





...MEAD

