

764 

WWUS20 KWNS 152021

SEL1

SPC WW 152021

COZ000-KSZ000-160400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 481

NWS STORM PREDICTION CENTER NORMAN OK

220 PM MDT THU JUL 15 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF EASTERN COLORADO

       FAR NORTHWEST KANSAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 220 PM UNTIL

1000 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 80

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF

LIMON COLORADO TO 40 MILES EAST SOUTHEAST OF TRINIDAD 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 479...WW 480...



DISCUSSION...FAVORABLE UPSLOPE REGIME WILL SUPPORT THE DEVELOPMENT

OF WIDELY SCATTERED TSTMS THROUGH THE REMAINDER OF THE AFTERNOON

INTO THIS EVENING.  AMBIENT BOUNDARY LAYER IS RATHER MOIST WITH

DEWPOINTS IN THE 50S TO LOW/MID 60S AND WHEN COUPLED WITH A STEEP

LAPSE RATE ENVIRONMENT...AIR MASS HAS BECOME MODERATELY UNSTABLE

WITH MLCAPE OF 1000-2500 J/KG.  WHILE MID AND HIGH-LEVEL WIND FIELD

IS NOT PARTICULARLY STRONG...PRONOUNCED VEERING WINDS WITH HEIGHT

AND RESULTANT 30-35 KT OF EFFECTIVE BULK SHEAR WILL SUPPORT ROTATING

STORMS WITH THE THREAT FOR LARGE HAIL AND LOCALLY DAMAGING WIND

GUSTS.



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 33020.





...MEAD

