

829 

WWUS20 KWNS 080223

SEL5

SPC WW 080223

MNZ000-WIZ000-LMZ000-081000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 585

NWS STORM PREDICTION CENTER NORMAN OK

915 PM CDT SAT AUG 7 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       A SMALL PART OF EASTERN MINNESOTA

       NORTHERN AND CENTRAL WISCONSIN

       LAKE MICHIGAN



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 915 PM

UNTIL 500 AM CDT.



HAIL TO 1.5 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 100 MILES NORTHWEST

OF EAU CLAIRE WISCONSIN TO 30 MILES EAST NORTHEAST OF GREEN BAY

WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 584...



DISCUSSION...TSTMS...INCLUDING A FEW SUPERCELLS...EXPECTED TO

INCREASE IN COVERAGE NEAR DIFFUSE WNW/ESE-ORIENTED STNRY FRONT OVER

CNTRL WI AS LLJ VEERS AND STRENGTHENS THROUGH LATER TONIGHT /REF MCD

1608/.  DIFFUSE NATURE OF FRONT AND ABSENCE OF STRONGLY-FOCUSED UPR

LVL FORCING FOR ASCENT SUGGEST THAT STORM MODE MAY REMAIN LARGELY

QUASI-DISCRETE.  GIVEN SUCH A STORM MODE AND MODERATELY-SHEARED LOW

TO MID LVL WIND FIELD...SETUP MAY SUPPORT A FEW SUSTAINED

SUPERCELLS.  THESE STORMS MAY REMAIN SLIGHTLY ELEVATED GIVEN

NOCTURNAL INCREASE IN CIN AND THE FACT THAT WEAK ISENTROPIC LIFT

SHOULD REMAIN THE MAIN SOURCE OF STORM INITIATION.  THUS...THE MAIN

SVR THREATS SHOULD BE HAIL AND LOCALLY DMGG WIND.  HOWEVER...SHOULD

THE STORMS BECOME MORE NEARLY SFC-BASED THAN IS NOW EXPECTED...A

CORRESPONDING INCREASE IN TORNADO RISK WOULD OCCUR /MOST LIKELY OVER

NW AND W CNTRL WI/...AND PARTS OF THE WW MAY REQUIRE UPGRADE TO

TORNADO.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 28030.





...CORFIDI

