Hail and Damaging Wind in Wisconsin, July 24, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1035 AM CDT MON JUL 24 2006

.UPDATE...CURRENT GOES WATER VAPOR LOOPS INDICATING AN ORGANIZED
SHORTWAVE TROUGH NEAR KFAR MOVING SOUTHEAST TOWARD THE FORECAST
AREA. THIS HAS ORGANIZED A SHOWER AREA WITH CG LIGHTNING
ACTIVITY OVER THE LAST FEW HOURS. MEANWHILE...THE LATEST SURFACE
ANALYSES FROM 13/14Z INDICATE A CONVERGENCE FRONTAL BOUNDARY
ASSOCIATED WITH SYSTEM OVER QUEBEC DRAGGING SOUTH INTO NRN WI/MN
ALONG A KPBH-KRPD-KSTC LINE. KDLH RADAR SHOWS ECHOES ON AND NORTH OF
THIS BOUNDARY WITH CG ACTIVITY TOO. 12Z RUC INDICATES THIS FRONT WILL
BE SUPPORTED BY 850MB THETA-E CONVERGENCE LATER THIS AFTERNOON NEAR
I-90. INSTABILITY IS GROWING IN CLEAR SKIES WITH A MOISTURE POOL
ALONG THE FRONT OF 65-70F DEWPOINTS. LAPS DATA SHOWING AROUND
1000J/KG OF MLCAPE AHEAD OF FRONT KEAU-KMDZ AND MORE HEATING ON THE
WAY. DEWPOINTS SHOULD POOL ALONG THE FRONT AND THIS POOL WILL DROP
SOUTH TODAY SO 67-70F WILL BE FOUND ALONG I-90 AND NORTH.

OVERALL...WITH SHORTWAVE TROUGH RIDING THE POLEWARD SIDE OF A WEAK
UPPER LEVEL SPEED MAX MOVING RIGHT AT THE FORECAST AREA....THE
FRONTAL POSITION TO BE JUST NORTH OF I-90 BY LATER AFTERNOON...AND
INSTABILITY THAT SHOULD BE AROUND 2000 J/KG MLCAPE WILL PROVIDE UPPER
FORCING...SURFACE TRIGGER...AND ENERGY FOR ENHANCED STORM COVERAGE
LATER THIS AFTERNOON AND EARLY EVENING. HAVE INCREASED THE CHANGE
FOR RAIN TO 40/50 BUT MAY NEED TO INCREASE THIS AGAIN BASED ON
EARLY AFTERNOON DEVELOPMENTS.

SEVERE THREAT...WITH THE INSTABILITY...HAIL AND WIND WILL BE THE
THREATS AS MIDSHIFT ADVERTISED. THE WIND SHEAR IS STILL IN THE VERY
LOW-LEVELS AND NOT DEEP SUPERCELL SHEAR. THE 0-3KM SHEAR TO ORGANIZE
THE COLD POOL IS MODERATE SO THIS COULD PROVIDE BRIEF MULTICELL
ORGANIZATION. THE BEST ORGANIZATION MAY COME FROM THE SHORTWAVE
TROUGH WHICH COULD PROVIDE AN ORGANIZED LINE MODE IN
HIGH INSTABILITY...POSSIBLY ENHANCING THE WIND THREAT. OUTLIER
MODES...POSSIBLY A SPIN UP TORNADO ON THE FRONT IF UPDRAFTS CAN TAP
THE LOW-LEVEL HELICITY PRESENT AND PERSIST. IF THE BOUNDARY
SLOWS/STOPS OVER THE FORECAST AREA...NON-SUPERCELL TORS COULD BE A
THREAT. HOWEVER...THIS SEEMS MUCH LESS LIKELY FOR TODAY.

TIMING...LATER THIS AFTERNOON NORTH OF I-90 WILL BE THE MAIN
THREAT...SLOWLY SHIFTING SOUTH/EAST WITH SHORTWAVE IN THE EARLY
EVENING. LEADING EDGE OF SHORTWAVE WILL BE ON A WABASHA-TAYLOR LINE
AROUND 5 PM.

UPDATE SENT.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

BAUMGARDT

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE LA CROSSE WI
1202 PM CDT MON JUL 24 2006

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-251100-
ADAMS-ALLAMAKEE-BUFFALO-CHICKASAW-CLARK-CLAYTON-CRAWFORD-DODGE-
FAYETTE-FILLMORE-FLOYD-GRANT-HOUSTON-HOWARD-JACKSON-JUNEAU-LA CROSSE-
MITCHELL-MONROE-MOWER-OLMSTED-RICHLAND-TAYLOR-TREMPEALEAU-VERNON-
WABASHA-WINNESHIEK-WINONA-
1202 PM CDT MON JUL 24 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST IOWA...
SOUTHEAST MINNESOTA...AND SOUTHWEST INTO CENTRAL WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

INSTABILITY CONTINUES TO GROW ACROSS THE AREA THIS AFTERNOON AND A
COLD FRONT WAS LOCATED FROM RHINELANDER WISCONSIN TO MINNEAPOLIS
MINNESOTA AT 12 PM. THIS COLD FRONT WILL CONTINUE TO MOVE SOUTH TO
AROUND THE I-90 CORRIDOR BY LATE AFTERNOON /5-6 PM/. THIS FRONT WILL
BE THE TRIGGER AND FOCUS FOR THUNDERSTORM ACTIVITY. WINDS ALOFT ARE
NOT OVERLY FAVORABLE...BUT SOME OF THESE STORMS WILL LIKELY BECOME
SEVERE BECAUSE OF THE INSTABILITY THIS AFTERNOON AND EVENING. THE
STORMS WILL TRY TO PRESS SOUTH INTO NORTHEAST IOWA AND SOUTHWEST
WISCONSIN DURING THE EARLY TO MID-EVENING...HOWEVER CONFIDENCE IS
LOWER ON HOW FAR SOUTH THE FRONT AND STORMS WILL REACH BEFORE
STALLING. STORM INTENSITY WILL WEAKEN AFTER SUNSET.

LARGE HAIL AND DAMAGING WINDS ARE POSSIBLE...WITH THE GREATEST THREAT
OF SEVERE STORMS NEAR THE FRONTAL BOUNDARY. THIS IS MAINLY NORTH OF
A MASON CITY IOWA TO BOSCOBEL WISCONSIN LINE.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

MORE UPPER LEVEL DISTURBANCES ARE EXPECTED TO MOVE ACROSS THE
UPPER MIDWEST TUESDAY THROUGH THURSDAY. IN ADDITION...THE FRONTAL
BOUNDARY IS EXPECTED TO BE IN OR NEAR THE AREA PROVIDING A TRIGGER
FOR THUNDERSTORMS. DEPENDING ON WHERE THE FRONT MAY BE...HOW MUCH
INSTABILITY WILL BE AVAILABLE AND THE STRENGTH OF THE DISTURBANCES
AND WINDS ALOFT...THERE MAY BE A SEVERE THREAT WITH SOME OF THE
STORMS LATER IN THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY LATER THIS AFTERNOON AND THIS EVENING.
THE APPROXIMATE WINDOWS OF SPOTTER ACTIVATION ARE...

NORTH OF HIGHWAY 10 IN WISCONSIN...2 PM TO 7 PM...
ALONG THE I-90 CORRIDOR...4 PM TO 9 PM...
EXTREME NORTHEAST IOWA AND WISCONSIN RIVER VALLEY...6 PM TO 10 PM.

ADDITIONAL SPOTTER ACTIVATIONS MAY BE NEEDED AT TIMES FROM TUESDAY
THROUGH THURSDAY...BUT THE DETAILS OF THIS ARE LESS CERTAIN.

.EMERGENCY MANAGEMENT COORDINATION...

NO CALL IS SCHEDULED.

RRS/MW/BAUMGARDT