WATCHES: Severe Thunderstorm Watch Number 679

WWUS20 KWNS 090126
SEL9
SPC WW 090126
COZ000-NEZ000-WYZ000-090600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 679
NWS STORM PREDICTION CENTER NORMAN OK
730 PM MDT SAT AUG 8 2009

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

NORTHEAST COLORADO
NEBRASKA PANHANDLE
SOUTHEAST WYOMING

EFFECTIVE THIS SATURDAY NIGHT FROM 730 PM UNTIL MIDNIGHT 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 EAST AND WEST OF A LINE FROM 15 MILES NORTH
NORTHEAST OF CHADRON NEBRASKA TO 75 MILES SOUTHWEST OF SIDNEY
NEBRASKA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).

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 678...

DISCUSSION...WELL DEFINED SHORTWAVE TROUGH MOVING NEWD ACROSS THE
CENTRAL ROCKIES WILL CONTINUE TO SUPPORT STRONG/SEVERE THUNDERSTORM
DEVELOPMENT OVER THE HIGH PLAINS THROUGH THE EVENING. AIR MASS
REMAINS QUITE MOIST INTO WRN NEB/NERN CO AND WILL SUSTAIN MARGINAL
INSTABILITY. SHEAR WILL BE SUPPORTIVE OF SUPERCELLS...ENHANCING THE
RISK OF LARGE HAIL GIVEN VERY STEEP MID LEVEL LAPSE RATES.

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 25030.

...EVANS

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.