Severe Thunderstorm Warning 165, NWS La Crosse, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
220 PM CDT MON SEP 11 2000

PRIMARY CONCERN...SEVERE WEATHER POTENTIAL INTO THIS EVENING.

SURFACE ANALYSIS INDICATED LOW PRESSURE IN SOUTHEAST MN...MOVING
ALONG FRONTAL BOUNDARY EXTENDING FROM NORTHWEST WI TO WESTERN IOWA.
AIR MASS VERY MOIST AND UNSTABLE AHEAD OF THE FRONT WITH MSAS
INDICATING LIFTED INDICES OF MINUS 8 AND GOOD LOW LEVEL MOISTURE
CONVERGENCE. SHORT WAVE SEEN IN WATER VAPOR IMAGERY ADVANCING ACROSS
THE NORTH DAKOTA/CANADIAN BORDER AS UPPER LEVEL TROUGH AMPLIFIES.

12Z MODELS INITIALIZED WELL AND AGREE THAT UPPER LEVEL TROUGH WILL
MOVE RAPIDLY TOWARD THE GREAT LAKES TONIGHT...SWEEPING THE ASSOCIATED
SURFACE COLD FRONT QUICKLY ACROSS THE FORECAST AREA THIS EVENING.
WITH RESPECT TO DETAILS...PREFER THE ETA MODEL OVERALL...ESPECIALLY
WITH DEPICTION OF QPF ASSOCIATED WITH STRONG CONVECTION THIS EVENING.

ALL PARAMETERS STILL POINT TO POTENTIAL FOR SEVERE WEATHER IN THE
FORECAST AREA LATE THIS AFTERNOON INTO THIS EVENING AS THE COLD FRONT
MOVES THROUGH. ATMOSPHERE QUITE UNSTABLE WITH CAPES OF 3000-4000
J/KG...K AND LIFTED INDICES OF 35 TO 40 AND MINUS 8 RESPECTIVELY.
IN ADDITION...STRONG UPPER LEVEL DIVERGENCE NOTED ASSOCIATED WITH 100
KNOT 300 MB JET ALONG THE U.S./CANADIAN BORDER PROVIDES LARGE SCALE
ASCENT TO FUEL DEEP CONVECTION.

DUE TO STEADY PACE OF COLD FRONT...STORMS EXPECTED TO MOVE ALONG
RATHER QUICKLY AND EXIT THE FORECAST AREA THIS EVENING. THIS SHOULD
PRECLUDE ANY POTENTIAL FOR FLASH FLOODING FOR OUR NORTH CENTRAL WI
ZONES WHERE 2 TO 4 INCHES OF RAIN FELL LAST NIGHT. THEREFORE...WILL
PLAN TO CANCEL FLASH FLOOD WATCH THAT WAS TO BE IN EFFECT THROUGH
THIS EVENING FOR THAT AREA.

WEATHER NIL NEXT SEVERAL DAYS...AS HIGH PRESSURE BUILDS IN WITH MUCH
COOLER AND DRIER AIR MASS. NEXT FRONTAL BOUNDARY EXPECTED TO MOVE
INTO THE AREA WEDNESDAY...BUT THIS SYSTEM SHOULD PASS THROUGH DRY AS
MOISTURE WILL BE LIMITED.

CURRENT FORECAST TEMPERATURES APPEAR TO BE ON TARGET BASED ON
FORECAST SOUNDINGS. THIS SUPPORTS LOWS IN THE MIDDLE 40S TO MIDDLE
50S...WHILE DAYTIME HIGHS REACH THE UPPER 60S TO MIDDLE 70S NEXT
COUPLE OF DAYS.

.LSE...NONE.

THOMPSON

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
1243 PM CDT MON SEP 11 2000

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

1008 PM    5 E FOUNTAIN CITY         WI   .75 INCH HAIL
09/10/00   BUFFALO                        REPORTED BY THE PUBLIC.

1010 PM    BELLINGER                 WI   WIND DAMAGE
09/10/00   TAYLOR                         REPORTED BY SHERIFF DEPT.

SHEA

N

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
459 PM CDT MON SEP 11 2000

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

0455 PM    ELLENBORO                 WI   .75 INCH HAIL
09/11/00   GRANT                          DIME SIZE HAIL REPORTED BY
                                          STORM SPOTTERS AND            X
                                          EMERGENCY MANAGER.

SHEA

N

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
529 PM CDT MON SEP 11 2000

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

0440 PM    1 N CUBA CITY             WI   1.25 INCH HAIL
09/11/00   GRANT

0440 PM    4 W CUBA CITY             WI   1 INCH HAIL
09/11/00   GRANT

0455 PM    ELLENBORO                 WI   .75 INCH HAIL
09/11/00   GRANT                          REPORTED BY SPOTTERS AND
                                          EMERGENCY MANAGER.

0508 PM    DICKEYVILLE               WI   60 MPH WIND GUST
09/11/00   GRANT                          REPORTED BY FIRE
                                          DEPARTMENT.

0510 PM    DICKEYVILLE               WI   WIND DAMAGE
09/11/00   GRANT                          LARGE TREES DOWN.

SHEA

N