Damaging Wind in Wisconsin, June 20, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
203 PM CDT MON JUN 20 2005

.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT

FORECAST CHALLENGE WILL CONTINUE TO BE RAIN CHANCES AND ATTEMPT AT
TIMING AS SHORT WAVE TROUGHS ROTATE OVER LARGE UPPER RIDGE. DETAILS
VERY DIFFICULT TO DISCERN UNLESS RIDGE BUILDS IN STRONGER TO PUSH
STORM COMPLEXES FARTHER NORTH.

OBVIOUS FOCUS IN SHORT TERM IS MCS MOVING THROUGH MPX FORECAST AREA
THIS AFTERNOON. WIND SHEAR AND CAPE VALUES DROP OFF CONSIDERABLY TO
THE SOUTHEAST OF LINE...CLOSER TO OUR FORECAST AREA...ALTHOUGH
3-HOUR PRESSURE FALLS ARE NOW CENTERED MORE ON REGION AND SURFACE
BASED CAPE VALUES HAVE BEEN INCREASING. CONFIDENCE IN HOW FAR
SOUTHEAST THIS LINE WILL GO IS LOW BUT WILL CERTAINLY BE RAISING
POPS INTO LIKELY CATEGORY FOR NORTHERN HALF OF FORECAST AREA THIS
EVENING. GIVEN SEVERE WEATHER PARAMETERS DROP OFF...CONVECTIVE LINE
MAY BECOME MORE EAST-WEST ORIENTATED AND MAINLY A HEAVY RAIN THREAT.

MEANWHILE SURFACE CONVERGENCE AS INCREASED WELL WEST OF AREA SO MORE
REDEVELOPMENT LOOKS ON TAP ACROSS EASTERN SOUTH DAKOTA AND SOUTHWEST
MINNESOTA. CORFIDI VECTORS SUGGEST THIS COMPLEX WOULD DROP SOUTH OR
SOUTHEAST INTO HIGHER CAPE VALUES AND MAY STAY WEST AND SOUTH OF
FORECAST AREA ALL TOGETHER.

SHORT TERM MODELS HINT AT MORE EASTERLY FLOW DEVELOPS ON TUESDAY
WITH BOUNDARY JUST SOUTH AND WEST OF AREA. DECENT LOW LEVEL MOISTURE
CONVERGENCE RE-ORGANIZES TUESDAY NIGHT ALONG THIS BOUNDARY SO MUCH
OF TUESDAY MAY BE QUIET. AFTER THAT...AS UPPER RIDGE TRIES TO BUILD
BACK NORTH...QUESTION WILL BE WILL MCS ACTIVITY MOVE NORTH OR BE
HELD UP BY OUTFLOW BOUNDARIES KEEPING RAIN THREAT OVER AREA LONGER
THAN MODELS MAY SUGGEST. IN ANY EVENT...BEST RAIN THREAT IN OUR
COUNTY WARNING AREA APPEARS TO BE NIGHTTIME HOURS BUT WILL KEEP
CHANCE POPS GOING FOR TIME BEING WITH NO WAY TO WEED OUT DETAILS.

.LONG TERM...FRIDAY THROUGH MONDAY

UPPER RIDGE FLATTENS OUT BY FRIDAY ALLOWING SURFACE COLD FRONT TO
WORK ACROSS UPPER MIDWEST. RAIN THREAT...AND LIKELY SEVERE RISK...
LOOKS TO BE MORE ORGANIZED AT THE END OF THE WEEK...BUT TRIED TO
KEEP DRY TREND OVER WEEKEND IN BETWEEN SYSTEMS...AS UPPER RIDGE
BUILDS BACK. MORE MCS ACTIVITY LIKELY AS RIDGE BUILDS BUT WANTED TO
KEEP DRIER TREND WITH NO SPECIFICS OF TIMING OR LOCATION. OVERALL
PATTERN CHANGES LITTLE WITH WARM WEATHER AND OCCASIONAL MCS RISKS.

&&

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

SHEA

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE LA CROSSE WI
1202 PM CDT MON JUN 20 2005

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-211100-
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 JUN 20 2005

CORRECTED SECOND PARAGRAPH DAY ONE

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

A LINE OF STRONG TO SEVERE THUNDERSTORMS MOVING ACROSS CENTRAL
MINNESOTA AT MID DAY WILL CONTINUE TO MOVE EAST AND SOUTHEAST THIS
AFTERNOON. INSTABILITY WILL CONTINUE TO INCREASE OVER THE AREA THIS
AFTERNOON...ALONG WITH THE WINDS ALOFT. BOTH OF THESE WILL BE
FAVORABLE FOR THE LINE OF THUNDERSTORMS TO MAINTAIN ITS STRENGTH AS
IT MOVES SOUTHEAST TOWARD THE AREA. THE STORM PREDICTION CENTER
INDICATES THERE IS A SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON AND
EARLY THIS EVENING...NORTH AND WEST OF A LINE FROM CHARLES CITY IOWA
TO LA CROSSE AND WISCONSIN RAPIDS. THE MAIN THREAT WITH THESE STORMS
WILL BE DAMAGING STRAIGHT-LINE WINDS AND LARGE HAIL.

A WEAK COLD FRONT WILL SAG SOUTH INTO CENTRAL WISCONSIN AND SOUTHERN
MINNESOTA LATER TONIGHT. THIS WILL CONTINUE THE CHANCE OF
THUNDERSTORMS. DUE TO WEAKER WIND SHEAR ALOFT AND LESS
INSTABILITY...ANY THUNDERSTORMS THAT DO DEVELOP LATER TONIGHT ARE
NOT EXPECTED TO BECOME SEVERE.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS WILL BE POSSIBLE AGAIN TUESDAY INTO TUESDAY EVENING AS
A FRONTAL BOUNDARY LINGERS ACROSS THE AREA. DUE TO THE AMOUNT OF
INSTABILITY AND AN INCREASE IN WIND SHEAR...A FEW OF THESE STORMS
COULD BECOME SEVERE.

THUNDERSTORMS WILL BE POSSIBLE AGAIN FROM WEDNESDAY NIGHT THROUGH
FRIDAY NIGHT AS SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE
AREA. AT THIS TIME IT APPEARS THAT NONE OF THESE STORMS ARE EXPECTED
TO BE SEVERE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO EARLY THIS
EVENING ACROSS SOUTHEAST MINNESOTA...PARTS OF NORTHEAST IOWA AND
INTO WEST CENTRAL AND CENTRAL WISCONSIN. THE MAIN THREAT TIME WILL
BE BETWEEN 3 PM AND 8 PM.

.EMERGENCY MANAGEMENT COORDINATION...

NO CALL IS SCHEDULED.

RRS