

793 

WWUS20 KWNS 082333

SEL1

SPC WW 082333

MNZ000-WIZ000-090700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 591

NWS STORM PREDICTION CENTER NORMAN OK

630 PM CDT SUN AUG 8 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN MINNESOTA

       WEST CENTRAL AND NORTHWEST WISCONSIN



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 630 PM UNTIL

200 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES NORTH

NORTHWEST OF REDWOOD FALLS MINNESOTA TO 55 MILES EAST OF EAU

CLAIRE WISCONSIN.  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 587...WW 588...WW

589...WW 590...



DISCUSSION...TSTMS HAVE FORMED RECENTLY ALONG WEAK W/E BOUNDARY N OF

THE MSP AREA.  OTHER STORMS HAVE AT THE SAME TIME DEVELOPED IN AREA

OF ELEVATED INSTABILITY IN SW MN.  ALL OF THE ACTIVITY LIKELY IS

BEING ENHANCED BY PASSING UPR LVL IMPULSE /PER WATER VAPOR

IMAGERY/... AND...IN ERN MN...BY SFC HEATING.  LOW LVL WINDS ARE

EXPECTED TO REMAIN WEAK/DISORGANIZED.  BUT PRESENCE OF HI PW WITH

MODERATE TO SEASONABLY STRONG DEEP WNWLY SHEAR /PER VWP AND PROFILER

DATA/ MAY SUPPORT ESE-PROPAGATING BOWING SEGMENTS WITH LOCALLY DMGG

WIND.



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 29025.





...CORFIDI

