Strong to severe thunderstorms, causing damaging winds, a tornado, and flash flooding, hit mainly southern Wisconsin June 12 2008 - Thursday afternoon and evening. Particularly hard hit was Grant County, WI, where flash flooding closed numerous roads, destroyed 2 homes, and forced evacuations and rescues.  Many secondary roads and bridges were damaged due to the flooding.

The radar loop below is from 2 pm to 6 pm on June 12 showing the "training" thunderstorms across Grant County leading to the flash flooding. The "training" thunderstorms refers to the similarity to a train’s cars running over the same spot. These thunderstorms formed in Iowa and continued to move over the same locations in Grant County.

Area of Straight Line Wind Damage and Brief Tornado: A sporadic path of straight line wind damage was noted from Ellenboro to about 2 miles northeast of Union. This is about 6 miles in length and about 3 miles wide in a polygon area east of the line from Ellenboro through Union. See the images below for this damage lay out.

Most of the straight line wind damage would have occurred from winds of 60 mph but isolated 80 mph winds could not be ruled out. Cross winds were strong enough to push the rear of a spotter’s SUV 2 feet over on the road on a north-south oriented highway. The wind direction within the damage area was from the southwest to northeast and occurred from about 2:20 pm to 2:40 pm.  The wind damage was mainly isolated downed trees and limbs as well as damaged metal farm outbuildings. A few smaller, weaker sheds were moved or destroyed.

Along the same path of the straight line wind damage was a brief tornado. The tornado occurred about 2:29 pm 0.6 miles northeast of Union or about 0.2 miles north of the intersection of Town Hall Road and County A-D. The tornado only had a brief touch down with winds estimated in the 70-80 mph range which would make it an EF0 tornado on the enhanced Fujita scale. The tornado caused an enhanced area of tree damage with a few 18" diameter pines snapped off 15 feet above the ground. Power lines were downed near the residence and farm that was struck, but the house sustained little damage. Windows remained unbroken. Within the wind damage area overall, little home damage occurred unless caused by fallen trees.

Damage Map	Mud/dirt debris on siding of garage. Windows remained unbroken.	Fallen trees in front yard of residence.	Snapped pines in backyard.
Oak stand damaged with debris convergent toward house (lying west to east).

Storm Total Radar Estimated Precipitation For June 12:

An area across central Grant County received over 4 inches of rain in a few hours on Thursday as seen by the orange area. Hard hit communities included Potosi, Tennyson, and British Hollow. Tributary creeks and streams that flood as they flowed into the Platte River. Many roads and bridges were washed out on county and secondary roads in the vicinity of the Platte River. Some images from the flooding:

Culvert clogs at the intersection of two streams under Highway	Property damage to work shed and high water mark from clogged culvert	Potosi during flash flooding	Potosi during flash flooding
Potosi during flash flooding	Potosi during flash flooding

Measured Rainfall Reports From Thursday June 12 2008 at 7am to Friday June 13 2008 at 7am

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
808 AM CDT FRI JUN 13 2008

...24 HOUR RAINFALL TOTALS ACROSS THE AREA...

LOCATION RAINFALL TIME LAT/LON
 

IOWA

...ALLAMAKEE COUNTY...
DORCHESTER 0.57 0700 AM 43.47N 91.51W
POSTVILLE 0.48 0700 AM 43.09N 91.56W
LANSING 4SE 0.43 0700 AM 43.32N 91.16W
ION 0.15 0700 AM 43.11N 91.27W
YELLOW RIVER PARK 0.13 0700 AM 43.17N 91.24W

...CLAYTON COUNTY...
EDGEWOOD 2.51 0700 AM 42.65N 91.40W
GARBER 1.47 0700 AM 42.74N 91.26W
LITTLEPORT 0.56 0700 AM 42.75N 91.37W
GUTTENBERG DAM 10 0.55 0700 AM 42.79N 91.10W
STRAWBERRY POINT 0.33 0700 AM 42.69N 91.53W
ELKADER 6SSW 0.26 0700 AM 42.79N 91.45W
MARQUETTE 0.26 0700 AM 43.04N 91.21W
ELKADER 0.13 0700 AM 42.84N 91.40W
VOLGA 1NE 0.12 0700 AM 42.81N 91.52W
MCGREGOR 0.08 0700 AM 43.02N 91.17W
 

...FLOYD COUNTY...
CHARLES CITY AWOS 0.12 0700 AM 43.07N 92.61W
CHARLES CITY COOP 0.07 0700 AM 43.08N 92.67W

...HOWARD COUNTY...
CRESCO 0.88 0700 AM 43.37N 92.11W
ELMA 0.10 0700 AM 43.24N 92.44W

...MITCHELL COUNTY...
ST ANSGAR 0.04 0700 AM 43.37N 92.83W

...WINNESHIEK COUNTY...
WAUCOMA 3SE 1.22 0700 AM 43.02N 91.98W
DECORAH AWOS 0.63 0700 AM 43.28N 91.74W
BLUFFTON 0.29 0700 AM 43.41N 91.90W

MINNESOTA

...FILLMORE COUNTY...
HIGHLAND 2SE 0.81 0700 AM 43.65N 91.84W
LANESBORO 0.78 0700 AM 43.72N 91.97W
HARMONY 0.41 0700 AM 43.55N 92.01W
SPRING VALLEY 0.06 0700 AM 43.69N 92.39W

...HOUSTON COUNTY...
CALEDONIA 0.79 0700 AM 43.63N 91.50W
BROWNSVILLE 0.58 0700 AM 43.70N 91.27W
SPRING GROVE 4N 0.30 0700 AM 43.61N 91.62W

...MOWER COUNTY...
AUSTIN 0.17 0700 AM 43.67N 92.95W

...WABASHA COUNTY...
ZUMBRO FALLS 0.14 0700 AM 44.29N 92.42W

...WINONA COUNTY...
LA CRESCENT DAM 7 0.54 0700 AM 43.87N 91.31W
DAKOTA 0.26 0700 AM 43.92N 91.37W
WINONA DAM 5A 0.23 0700 AM 44.09N 91.67W
MINNESOTA CITY DAM 5 0.02 0700 AM 44.16N 91.81W

WISCONSIN

...ADAMS COUNTY...
FRIENDSHIP 0.66 0700 AM 43.98N 89.83W

...BUFFALO COUNTY...
ALMA DAM 4 0.00 0700 AM 44.33N 91.92W

...CLARK COUNTY...
NEILLSVILLE 3SW 0.40 0700 AM 44.53N 90.64W
NEILLSVILLE 0.28 0700 AM 44.56N 90.61W
OWEN 2N 0.06 0700 AM 44.98N 90.55W

...CRAWFORD COUNTY...
STEUBEN 0.92 0700 AM 43.18N 90.87W
PRAIRIE DU CHIEN 0.42 0700 AM 43.05N 91.13W
LYNXVILLE DAM 9 0.26 0700 AM 43.21N 91.10W

...GRANT COUNTY...
LANCASTER 4.18 0700 AM
ROCKVILLE 3.15 0700 AM 42.73N 90.64W
BURTON 2.74 0700 AM 42.72N 90.82W
CUBA CITY 1.45 0700 AM
BOSCOBEL ASOS 1.33 0700 AM 43.16N 90.68W

...JACKSON COUNTY...
BLACK RIVER FALLS 0.42 0700 AM 44.38N 90.84W
HATFIELD 0.21 0700 AM 44.42N 90.73W

...JUNEAU COUNTY...
NECEDAH 5WNW CRN 0.80 0700 AM 44.06N 90.17W
NECEDAH RAWS 0.54 0700 AM 44.02N 90.08W
NECEDAH 2SE 0.42 0700 AM 44.00N 90.04W

...LA CROSSE COUNTY...
LA CROSSE WFO 0.84 0700 AM 43.82N 91.19W
HOLMEN 0.53 0700 AM 43.97N 91.27W
LA CROSSE ASOS 0.44 0700 AM 43.88N 91.26W
HOLMEN 2S 0.36 0700 AM 43.93N 91.25W

...MONROE COUNTY...
TUNNEL CITY 1S 0.73 0700 AM 44.01N 90.57W

...RICHLAND COUNTY...
HUB CITY 1.76 0700 AM

...TAYLOR COUNTY...
DIAMOND LAKE RAWS 0.02 0700 AM 45.11N 90.69W

...TREMPEALEAU COUNTY...
TREMPEALEAU DAM 6 0.62 0700 AM 44.00N 91.44W
OSSEO 0.06 0700 AM 44.58N 91.22W

...VERNON COUNTY...
GENOA DAM 8 0.74 0700 AM 43.57N 91.23W
ONTARIO 0.46 0700 AM 43.72N 90.59W
LA FARGE 0.38 0700 AM 43.57N 90.64W

OBSERVATIONS ARE COLLECTED FROM A VARIETY OF SOURCES WITH VARYING
EQUIPMENT AND EXPOSURE. NOT ALL DATA LISTED IS CONSIDERED OFFICIAL.

Storm Reports From Thursday June 12

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE LA CROSSE WI
858 PM CDT THU JUN 12 2008

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

0145 PM TSTM WND DMG 4 N DICKEYVILLE 42.68N 90.59W
06/12/2008 GRANT WI EMERGENCY MNGR

SILO TOP BLOWN OFF AND BARN OR SHED BLOWN DOWN ALONG
COUNTY ROAD O NORTH OF DICKEYVILLE. WATER WAS OVER
FLOWING OVER SOME NEARBY ROADS.

0212 PM FLASH FLOOD TENNYSON 42.69N 90.69W
06/12/2008 GRANT WI EMERGENCY MNGR

SOME STREETS GETTING FLOODED.

0214 PM FLASH FLOOD 5 N DICKEYVILLE 42.70N 90.59W
06/12/2008 GRANT WI EMERGENCY MNGR

WATER OVER COUNTY ROADS O AND B.

0220 PM FLASH FLOOD 5 ENE POTOSI 42.72N 90.62W
06/12/2008 GRANT WI EMERGENCY MNGR

LOTS OF REPORTS OF FLOODING COMING INTO 911 CENTER.

0229 PM TSTM WND GST 4 N PLATTEVILLE 42.79N 90.48W
06/12/2008 E60.00 MPH GRANT WI TRAINED SPOTTER

ALSO DRIVING RAINS.

0230 PM TSTM WND DMG 2 S UNION 42.80N 90.52W
06/12/2008 GRANT WI TRAINED SPOTTER

ABOUT A 6 MILE AREA OF DAMAGE TO TREES NEAR COUNTY ROAD D
AND BUTSON ROAD.

0230 PM TSTM WND DMG 2 S UNION 42.80N 90.52W
06/12/2008 GRANT WI TRAINED SPOTTER

NUMEROUS BRANCHES DOWN. SOME FARM MACHINERY DAMAGED. LOTS
OF FLOODING BEING OBSERVED AS WELL.

0230 PM TSTM WND DMG 4 N PLATTEVILLE 42.79N 90.48W
06/12/2008 GRANT WI TRAINED SPOTTER

SPOTTER WAS BLOWN OFF COUNTY ROAD D FROM STRONG WINDS.

0240 PM FLASH FLOOD POTOSI 42.69N 90.71W
06/12/2008 GRANT WI EMERGENCY MNGR

HIGHWAYS 61 AND 81 CLOSED. REPORTS OF LP TANKS FLOATING
AND RESCUES NEEDED.

0327 PM FLASH FLOOD LANCASTER 42.85N 90.71W
06/12/2008 GRANT WI EMERGENCY MNGR

MAJOR FLOODING REPORTED IN LANCASTER...POTOSI...AND
PLATTEVILLE. MOST STATE HIGHWAYS CLOSED IN THE COUNTY.
STILL PERFORMING RESCUES.

0332 PM HAIL BIG FLATS 44.12N 89.80W
06/12/2008 E0.75 INCH ADAMS WI AMATEUR RADIO

0351 PM FLOOD 2 NW LONE ROCK 43.21N 90.23W
06/12/2008 RICHLAND WI AMATEUR RADIO

LOTS OF RUN OFF. DITCHES FILLING UP QUICK.

0354 PM HEAVY RAIN 4 W LANCASTER 42.85N 90.79W
06/12/2008 M3.30 INCH GRANT WI CO-OP OBSERVER

MEASURED AT LANCASTER AG STATION. MAJOR RUNOFF REPORTED.

0400 PM FLASH FLOOD 4 ESE RICHLAND CENTER 43.32N 90.31W
06/12/2008 RICHLAND WI AMATEUR RADIO

WATER OVER ROAD ON HIGHWAY 58 ABOUT 4 MILES FROM HIGHWAY
14.

0409 PM FLASH FLOOD 5 S RICHLAND CENTER 43.27N 90.38W
06/12/2008 RICHLAND WI AMATEUR RADIO

WATER OVER COUNTY ROADS O AND OO.

0428 PM FLASH FLOOD LANCASTER 42.85N 90.71W
06/12/2008 GRANT WI EMERGENCY MNGR

LIVINGSTON AND POTOSI ALSO HARD HIT. STATE HIGHWAYS 80
ADN 81 CLOSED. COUNTY ROADS U...N...A...AND D ALL CLOSED.
NUMEROUS TOWNSHIP ROADS WASHED OUT. NO TRAVEL IS
RECOMMENDED IN THE COUNTY.

0430 PM FLASH FLOOD POTOSI 42.69N 90.71W
06/12/2008 GRANT WI EMERGENCY MNGR

2 HOUSES DESTROYED IN POTOSI ON HIPPIE HOLLOW ROAD


&&

$$

BINAU