Hail and Damaging Wind in Wisconsin, May 30, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
305 PM CDT THU MAY 30 2002

FORECAST CONCERNS CONTINUE TO HINGE ON THE PCPN POSSIBILITIES.

LATEST SURFACE ANALYSIS HAD DEWPOINTS IN THE LOWER TO MIDDLE 60S
OVER THE AREA...WITH TEMPS GENERALLY IN THE UPPER 80S. A BOUNDARY
(DRY LINE/WARM) EXTENDED FROM A LOW NORTH OF MN TO AROUND THE RST
AREA AND THEN SOUTHWEST. A FEW OTHER BOUNDARIES WERE ALSO INDICATED.
LATEST 88-D IMAGERY INDICATED MOST OF THE CURRENT ACTIVITY OVER NE
WI...WITH SOME ISOLATED CELLS OVER NE IOWA.

NUMEROUS SFC/OUTFLOW BOUNDARIES...ALONG WITH VARIOUS WEAK UPPER
LEVEL DISTURBANCES...HAVE MADE IT DIFFICULT TO PIN-POINT TIMING AND
LOCATIONS FOR PCPN DEVELOPMENT OVER THE LAST COUPLE DAYS...AND THE
NEXT FEW LOOK SIMILAR. THE MAIN FEATURE TO FOCUS ON IS THE SFC
BOUNDARY PASSING EAST ACROSS THE AREA TODAY. PLENTY OF
INSTABILITY AVAILABLE FOR THE BOUNDARY TO TRIGGER LATE AFTERNOON AND
EVENING STORMS...MOSTLY OVER WI THOUGH. ORIGINALLY THOUGHT THIS
FRONT WOULD BE A BIT FARTHER EAST...BUT SLOWER MOVEMENT MEANS
EVENING STORM CHANCES FOR PARTS OF THE FORECAST AREA. THE NORTHERN
PART OF FRONT WILL CONTINUE TO MOVE EAST EARLY ON FRIDAY AS THE 500
MB TROUGH PUSHES EAST. HOWEVER...PART OF THE SFC BOUNDARY WILL LAY
UP TO THE SOUTH...LIKELY IN THE SOUTHERN IOWA TO CENTRAL ILL AREA.
THE MOISTURE RETURN IS PRETTY GOOD INTO THE BOUNDARY...WITH A 35 KT
LOW LEVEL JET NOSING INTO SW IA. SHOWERS AND THUNDERSTORMS SHOULD
DEVELOP INREPSONSE OVER IOWA AND NORTHERN ILL AS A RESULT. SOUTHERN
CUTS OF THE FORECAST AREA WILL HAVE A SHOT FOR SOME PCPN...BUT
POINTS NORTH LOOK TO STAY DRY. HOWEVER...AGAIN...IF THE FRONT LAYS
UP A BIT FARTHER NORTH...THE PCPN CHANCES WILL HAVE TO BE SHIFTED
NORTHWARD TOO. THE AVN SIDES WITH A MORE NORTHERN SOLUTION...WITH
THE ETA MORE SOUTH. WITH THE VARIABILITY AND UNCERTAINTY OF JUST
WHERE THE BOUNDARY WILL BE...WILL SPLIT THE DIFFERENCE FOR NOW.
SOMETHING TO KEEP A CLOSE EYE ON FOR THE NEXT COUPLE DAYS. MOST OF
FRIDAY THOUGH SHOULD BE NICE...WITH HIGH PRESSURE PROVIDING SOME
SUN AND NORTHWEST WINDS KEEPING TEMPS ONLY A FEW DEGREES COOLER THAN
TODAY.

FOR SATURDAY...THE EVER PRESENT BOUNDARY WILL STILL (PROBABLY) BE
JUST SOUTH OF THE AREA...WITH MORE SHOWERS AND STORMS AGAIN
DEVELOPING ALONG IT. STILL FEEL THE BEST CHANCES FOR RAIN WILL BE
SOUTH OF THE AREA...BUT THE SOUTHERN CUTS WARRANT POPS. AN ADVANCING
500 MB WAVE FROM THE SOUTHWEST WILL HELP MOVE THAT BOUNDARY BACK
NORTH AS A WARM FRONT...OVER SOUTHERN MN AND CENTRAL MN ON SUNDAY.
SHOULD HAVE A PRETTY GOOD SHOT FOR SOME ORGANIZED CONVECTION ACROSS
THE AREA BY SUNDAY NIGHT. AS WITH THE REST OF THE FORECAST...TIMING
IS UNCERTAIN...AND MODELS STILL SHOWING THE SAME DIFFERENCES AS
NOTED BEFORE.

.LSE...NONE

RIECK

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-310000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
1135 AM CDT THU MAY 30 2002

HAZARD - SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WIND.

TIMING - THIS AFTERNOON AND EVENING.

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

DISCUSSION - A WEAK COLD FRONT WILL MOVE ACROSS SOUTHEAST MINNESOTA
AND NORTHEAST IOWA THIS AFTERNOON...AND THROUGH SOUTHWEST AND
CENTRAL WISCONSIN THIS AFTERNOON AND EVENING. WITH PARTLY SUNNY
SKIES THIS AFTERNOON...TEMPERATURES WILL CLIMB INTO THE LOWER AND
MIDDLE 80S ACROSS THE REGION. IN ADDITION...THE SOUTH AND SOUTHWEST
WINDS THIS MORNING HAS HELPED THE SURFACE DEW POINTS TO CLIMB INTO
THE MIDDLE AND UPPER 60S. THE COMBINATION OF THE TEMPERATURES AND
DEW POINTS WILL CAUSE A RATHER UNSTABLE AIRMASS TO BE IN PLACE AHEAD
OF THE COLD FRONT. IN ADDITION...THE AREA WILL SEE GOOD VERTICAL
WIND SHEAR ALOFT. THIS WILL AID IN THE DEVELOPMENT SCATTERED
THUNDERSTORMS THIS AFTERNOON AND EVENING. A FEW OF THESE THUNDERSTORMS
MAY BECOME SEVERE. THE MAIN SEVERE WEATHER THREAT WILL BE LARGE HAIL
AND DAMAGING WINDS.

SPOTTER INFORMATION - SPOTTER ACTIVATION MAY BE NEEDED THIS
AFTERNOON AND EVENING.

BOYNE