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380 

WWUS20 KWNS 232339

SEL0

SPC WW 232339

WIZ000-240700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 680

NWS STORM PREDICTION CENTER NORMAN OK

635 PM CDT SAT JUL 23 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND SOUTHERN WISCONSIN



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 635 PM

UNTIL 200 AM CDT.



HAIL TO 1 INCH 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 70

STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH

NORTHWEST OF CAMP DOUGLAS WISCONSIN TO 35 MILES EAST SOUTHEAST OF

MADISON WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 679...



DISCUSSION...ELEVATED TSTM CLUSTER NOW NEAR EAU EXPECTED TO SLOWLY

INCREASE THROUGH THIS EVE AS 850-700 MB FLOW VEERS AND SLIGHTLY

STRENGTHENS IN WAKE OF MORNING MCS.  THE CURRENT STORMS APPEAR TO BE

ROOTED ATOP SHALLOW INVERSION/COOL DOME LEFT BY THAT CONVECTIVE

SYSTEM.  IF THE STORMS DO INDEED STRENGTHEN...COMBINATION OF 30-40

DEEP WNWLY SHEAR AND STEEPENING MID LVL LAPSE RATES SUGGESTS THE

POTENTIAL FOR BOWING SEGMENTS WITH LOCALLY DMGG WIND/MARGINALLY SVR

HAIL.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 30025.





...CORFIDI

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