WATCHES: Severe Thunderstorm Watch Number 341

WWUS20 KWNS 071702
SEL1
SPC WW 071702
COZ000-072300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 341
NWS STORM PREDICTION CENTER NORMAN OK
1100 AM MDT SUN JUN 7 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

NORTHEAST COLORADO

EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 1100 AM UNTIL
500 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 55
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTH OF
FORT COLLINS COLORADO TO 20 MILES EAST SOUTHEAST OF AKRON
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.

DISCUSSION...THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THE FRONT
RANGE IN THE MOIST UPSLOPE FLOW REGIME TO THE N OF A SLOW-MOVING
FRONT. SURFACE HEATING IN CLOUD BREAKS AND STEEP MID LEVEL LAPSE
RATES WILL CONTRIBUTE TO MODERATE INSTABILITY THROUGH THIS AFTERNOON
ON THE IMMEDIATE COOL SIDE OF THE BOUNDARY...AND STORM COVERAGE WILL
LIKELY INCREASE AS A MID LEVEL TROUGH MOVES NEWD FROM CENTRAL CO.
THE COMBINATION OF VERTICAL SHEAR AND STRONG DEEP LAYER VERTICAL
SHEAR WILL SUPPORT SUPERCELLS CAPABLE OF PRODUCING ISOLATED VERY
LARGE HAIL. ISOLATED DAMAGING WINDS WILL ALSO BE POSSIBLE...AND AN
ISOLATED TORNADO CANNOT BE RULED OUT.

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 26025.

...THOMPSON

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.