Tornado and Hail in Wisconsin, September 2, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
330 PM CDT MON SEP 2 2002

FOCUS IS ON THE RAIN CHANCE TONIGHT AND THEN POSSIBILITY AGAIN FOR
THURSDAY.

SURFACE ANALYSIS THIS AFTERNOON SHOWS A COLD FRONT FROM AROUND THE
KDLH AREA SOUTH TO KDSM AND INTO KANSAS. THUNDERSTORM ACTIVITY HAS
DEVELOPED AHEAD OF THE FRONT ACROSS NORTHERN WISCONSIN.

BOTH MODELS ARE IN GOOD AGREEMENT WITH THE SYSTEM FOR TONIGHT.
SHORT WAVE TROUGH WILL CONTINUE TO MOVE EAST ACROSS EXTREME SOUTHERN
CANADA. NOSE OF 100 KNOT JET WILL COMBINE WITH THE SHORT WAVE
TROUGH TO PRODUCE THE STRONGEST LIFT NORTH OF THE FORECAST AREA.
HOWEVER STILL EXPECTING AROUND 30 TO 50 UBAR/S OF LIFT AHEAD OF THE
FRONT. LAPS ANALYSIS INDICATES THE SURFACE BASED CAP IS GONE OVER
WESTERN WISCONSIN AND LESS THEN 80 J/KG IN CENTRAL WISCONSIN.
EXPECT ACTIVITY TO CONTINUE BUILDING SOUTH ALONG THE FRONT INTO THE
EVENING AND HAVE HIGHEST POPS FOR AREAS IN THE WATCH BOX. GIVEN THE
CURRENT POSITION OF THE FRONT...NOT EXPECTING ANY ACTIVITY FOR MUCH
OF NORTHEAST IOWA AND FOR PARTS OF SOUTHEAST MINNESOTA.

SURFACE HIGH PRESSURE WILL QUICKLY BUILD INTO THE AREA LATER
TONIGHT AND MONDAY. DRIER AIR WILL ACCOMPANY THE HIGH WITH LOWS IN
THE 50S THE NEXT TWO TO THREE NIGHTS.

THE HIGH WILL MOVE EAST OF THE REGION THURSDAY AS NEXT SYSTEM MOVES
INTO THE PLAINS. SOME CONCERN ABOUT THE POSSIBILITY FOR SHOWERS ON
THE BACK SIDE OF THE HIGH IN THE RETURN FLOW. BELIEVE THE AVN IS A
LITTLE TOO AGGRESSIVE WITH THE AMOUNT OF MOISTURE RETURNING THE AREA
AND IS A LITTLE TOO FAR SOUTH WITH THE LEAD SHORT WAVE TROUGH. THE
ETA EXTENSION OUT THROUGH 72 AND 84 HOURS KEEPS THE RAIN NORTHWEST
OF THE FORECAST AREA SO FOR NOW HAVE CONTINUED THE DRY FORECAST.

.LSE...NONE.

04

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-030200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
1226 PM CDT MON SEP 2 2002

HAZARD - SLIGHT TO MODERATE RISK OF SEVERE THUNDERSTORMS.

TIMING - THIS AFTERNOON AND EVENING.

LOCATION - NORTHEAST IOWA...SOUTHEAST MINNESOTA...SOUTHWEST AND
CENTRAL WISCONSIN.

DISCUSSION - A STRONG UPPER LEVEL DISTURBANCE...ACCOMPANIED WITH A
SURFACE COLD FRONT...WILL MOVE EAST ACROSS THE AREA THIS AFTERNOON
AND EVENING. AHEAD OF THIS DISTURBANCE...TEMPERATURES WILL CLIMB
INTO THE 85 TO 90 DEGREE RANGE. AT THE SAME TIME...OUR SURFACE DEW
POINTS WILL REMAIN AROUND 70 DEGREES. THIS WILL PRODUCE A VERY
UNSTABLE ATMOSPHERE ACROSS THE REGION. WARM AIR ALOFT IS PREVENTING
THUNDERSTORMS FROM CURRENTLY DEVELOPING ALONG THE COLD FRONT.
HOWEVER...AS THE ATMOSPHERE COOLS ALOFT...SCATTERED THUNDERSTORMS
MAY DEVELOP ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA BETWEEN
1 PM AND 5 PM THIS AFTERNOON. IF THESE THUNDERSTORMS DEVELOP...SOME
MAY BECOME SEVERE. THE PRIMARY THREAT WILL BE DAMAGING WINDS
AND LARGE HAIL.

MEANWHILE...OVER WESTERN AND CENTRAL WISCONSIN...THE ATMOSPHERE WILL
LIKELY COOL ENOUGH ALOFT FOR SCATTERED TO NUMEROUS THUNDERSTORMS TO
DEVELOP BETWEEN 3 PM AND 8 PM. SOME OF THESE THUNDERSTORMS WILL
LIKELY BECOME SEVERE. THE PRIMARY THREAT WILL BE LARGE HAIL AND
DAMAGING WINDS...BUT THERE THEY MAY BE ENOUGH TURNING IN THE LOW
LEVELS FOR AN ISOLATED TORNADO.

SPOTTER INFORMATION - THE LA CROSSE RADAR WILL BE DOWN THROUGH THIS
SEVERE WEATHER EVENT...SO WE WILL RELY ON NEARBY RADARS AND SPOTTER
REPORTS TO HELP US EVALUATE THE SEVERE WEATHER SITUATION. SPOTTER
ACTIVATION APPEARS LIKELY THIS AFTERNOON AND EVENING.

BOYNE

MNZ079-086-087-094-022300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
454 PM CDT MON SEP 2 2002

THE SEVERE THUNDERSTORM WATCH HAS BEEN CANCELED FOR THE FOLLOWING
COUNTIES...

IN MINNESOTA...
     WABASHA...DODGE...OLMSTED AND MOWER.

THIS INCLUDES THE CITIES OF...AUSTIN...DODGE CENTER...LAKE CITY...
MANTORVILLE AND ROCHESTER.

A COLD FRONT MOVING THROUGH THE AREA HAS PUSHED THE SEVERE WEATHER
THREAT TO THE EAST.  THEREFORE...THE SEVERE THUNDERSTORM WATCH HAS
BEEN CANCELED FOR WABASHA...DODGE...OLMSTED AND MOWER COUNTIES.

KRC