Severe Thunderstorm Warning 38, NWS La Crosse, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
329 AM CDT FRI JUL 4 2003

FORECAST CONCERNS ARE THE ONGOING SEVERE WEATHER THREAT EARLY THIS
MORNING...THEN PRECIPITATION CHANCES AND TEMPERATURES OVER THE NEXT
SEVERAL DAYS.

07Z SURFACE ANALYSIS RATHER COMPLICATED WITH ONGOING CONVECTION.
MAIN SURFACE BOUNDARY EXTENDS FROM NORTHWEST WISCONSIN...BACK
THROUGH SOUTHERN MINNESOTA AND INTO SOUTH DAKOTA. NUMEROUS OUTFLOW
BOUNDARIES WERE FOUND ACROSS MINNESOTA AND NORTHERN IOWA. LARGE AREA
OF CONVECTION...IN THE FORM OF LINEAR BOW ECHOS FOUND ACROSS NORTHERN
IOWA AND SOUTHERN MINNESOTA MOVING RAPIDLY EASTWARD. THESE HAVE
BEEN PRODUCING DAMAGING WIND GUSTS. CURRENT EXTRAPOLATION SHOULD
PUT IN TO THE EAST OF THE FORECAST AREA BETWEEN 12Z-14Z.

00Z/JULY 4TH MODELS DID A POOR JOB OF INITIALIZING CURRENT
CONVECTION...ESPECIALLY IN THEIR QPF FIELDS...AND GFS TOO ROBUST
WITH THEIR PRECIPITABLE WATER VALUES ACROSS EASTERN IOWA. MODEL MASS
FIELDS ARE IN GOOD AGREEMENT THROUGH THE FORECAST CYCLE...ALTHOUGH
DIFFERENCES DO APPEAR IN THE DETAILS. HAVE GENERALLY USED A BLEND
OF THE MODELS FOR THIS FORECAST. NEARLY ZONAL FLOW ACROSS TH
NORTHERN TIER OF STATES TO CONTINUE INTO THE WEEKEND.

IN THE SHORT TERM...CURRENT CONVECTION MOVING RAPIDLY EASTWARD. WITH
ITS CURRENT MOVEMENT...BULK OF SEVERE WEATHER WILL BE EAST OF THE
AREA BY 7 AM. MAIN SURFACE TROUGH TO MOVE ACROSS THE FORECAST AREA
TODAY...WITH PLENTY OF OUTFLOW BOUNDARIES AROUND THE AREA. ALTHOUGH
ATMOSPHERE TO BE WELL WORKED OVER THIS MORNING...SOME SUN THIS
AFTERNOON MAY ALLOW ENOUGH INSTABILITY TO BUILD FOR MORE
CONVECTION. FEEL BEST CHANCES WOULD BE ACROSS THE SOUTHERN TIER OF
COUNTIES. FOR THIS REASON WILL KEEP CHANCE POPS GOING.

AS BOUNDARY CONTINUES TO PUSH EAST TONIGHT...WEAK HIGH BUILDS INTO
THE AREA. MODELS PROG A LITTLE DRIER AIR TO WORK ITS WAY INTO THE
AREA. WILL KEEP THE LINGERING CHANCES ACROSS THE SOUTHERN ZONES
DURING THE EVENING HOURS. QUIET WEATHER THEN TO CONTINUE INTO
SATURDAY AS BOUNDARY REMAINS TO OUR SOUTH. THIS BEGINS TO MOVE
NORTHWARD ON SUNDAY...AS SURFACE LOW DEEPENS ACROSS THE NORTHERN
PLAINS. ONCE AGAIN MOISTURE BEGINS TO RETURN TO THE AREA AS
INSTABILITIES INCREASE. BOTH ETA AND GFS WANT TO PUSH TROUGH TOWARD
AREA ON SUNDAY. CURRENT FORECAST OF CHANCE POPS IN THIS TIME FRAME
LOOKS GOOD AND PLAN NO CHANGES AT THIS TIME.

GUIDANCE TEMPERATURES LOOK REASONABLE SO PLAN NO MAJOR DEVIATIONS.
DID UP HIGH TEMPERATURES BOTH TODAY AND SATURDAY A FEW DEGREES FROM
PREVIOUS FORECAST.

.LSE...WATCHES/WARNINGS/ADVISORIES...NONE.

RABERDING

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-041100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
1151 AM CDT THU JUL 3 2003

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

.DAY ONE...TODAY AND TONIGHT

A WEAK COLD FRONT OVER CENTRAL MINNESOTA WILL TRACK EAST INTO
WESTERN WISCONSIN LATE THIS AFTERNOON. DUE TO THE UNSTABLE AIR MASS
OUT AHEAD OF THE FRONT...SHOWERS AND THUNDERSTORMS ARE POSSIBLE
ACROSS SOUTHEAST MINNESOTA...NORTHEAST IOWA...SOUTHWEST AND CENTRAL
WISCONSIN. WITH THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS OVER
PARTS OF SOUTHWEST AND CENTRAL WISCONSIN. NONE OF THESE STORMS
HOWEVER ARE EXPECTED TO BE ORGANIZED OR SEVERE.

THE COLD FRONT WILL TRACK EAST INTO CENTRAL WISCONSIN BY LATE THIS
EVENING...AND THEN BECOME STATIONARY. A LOW PRESSURE SYSTEM OVER
SOUTH DAKOTA WILL MOVE EAST AND INTERACT WITH THE STALLED
FRONT...SPREADING SHOWERS AND THUNDERSTORMS ACROSS THE AREA TONIGHT.
SOME OF THE STORMS MAY BECOME SEVERE WITH DAMAGING WINDS AND LARGE
HAIL BEING THE PRIMARY THREAT. HEAVY RAINFALL WILL ALSO BE LIKELY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE COLD FRONT WILL SLIP SOUTH INTO NORTHERN ILLINOIS BY FRIDAY
MORNING. A WAVE OF LOW PRESSURE WILL RIDE EAST ALONG THIS FRONT
YIELDING A CHANCE OF THUNDERSTORMS...MAINLY ACROSS SOUTHWEST
WISCONSIN...SOUTHEAST MINNESOTA...AND NORTHEAST IOWA. THERE IS A
SLIGHT RISK THAT SOME OF THE STORMS MAY BECOME SEVERE WITH LARGE
HAIL AND DAMAGING WINDS.

THE NEXT CHANCE OF THUNDERSTORMS WILL COME ALONG SUNDAY INTO MONDAY
AS A LOW PRESSURE SYSTEM AND COLD FRONT MOVE EAST TOWARD THE AREA
FROM THE NORTHERN PLAINS. AT THIS TIME...ORGANIZED SEVERE WEATHER IS
NOT ANTICIPATED FOR THOSE DAYS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BECOME NECESSARY TONIGHT OVER PARTS OF
SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND WEST-CENTRAL WISCONSIN.

DTJ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
0248 AM CDT FRI JUL 04 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0245 AM    WALTHAM                   MN   60 MPH TSTORM WIND
07/04/03   MOWER

MW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
0308 AM CDT FRI JUL 04 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0307 AM    SPRING VALLEY             MN   WIND DAMAGE
07/04/03   FILLMORE                       LARGE TREE DOWN ONTO HOUSE

MW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
0320 AM CDT FRI JUL 04 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0225 AM    OSAGE                     IA   WIND DAMAGE
07/04/03   MITCHELL                       LARGE TREE DOWN

0225 AM    ORCHARD                   IA   WIND DAMAGE
07/04/03   MITCHELL                       LARGE TREES DOWN

MW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
0328 AM CDT FRI JUL 04 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0324 AM    WEST UNION                IA   63 MPH TSTORM WIND
07/04/03   FAYETTE                        MEASURED WIND SPEED 63 MPH

MW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
0342 AM CDT FRI JUL 04 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0252 AM    NEW HAMPTON               IA   WIND DAMAGE
07/04/03   CHICKASAW                      LARGE TREES DOWN

MW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
0350 AM CDT FRI JUL 04 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0255 AM    HAYFIELD                  MN   WIND DAMAGE
07/04/03   DODGE                          LARGE TREE BRANCHES DOWN
                                          BLOCKING STREETS

MW