EF2 tornado, Causeway to Big Flats, Wisconsin, April 10, 2011

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mph

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mphthis tornado

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF2

Date

April 10, 2011

Touchdown

6:12 PM CDT (23:12 UTC)

Lifted

6:30 PM CDT (23:30 UTC)

On the ground

18 minutes

Path length

17.1 miles (27.5 km)

Path width

800 yards (732 m)

Deaths

0

Injuries

0

Property damage

$3.3 million

County

Adams County

Touchdown point

44.022, -89.955

Lift-off point

44.073, -89.618

Record number

1104101712-01

A cold front pushed east into Wisconsin during the late afternoon and evening hours of April 10th. Severe thunderstorms developed along the cold front and produced very large hail and three tornadoes over portions of western and central Wisconsin. The hail ranged from quarter to tennis ball size and caused extensive damage to siding and cars in the southern portions of the city of La Crosse (La Crosse County). Although difficult to estimate, damage estimates from insurance companies and contractors in the area were between 20 and 30 million dollars from the one hail storm. National Weather Service storm survey teams confirmed two EF1 tornadoes and an EF2 tornado in Juneau and Adams counties. The tornadoes uprooted trees, knocked power lines down, flipped automobiles, and damaged or destroyed homes and businesses. In Adams County, 7 homes and 3 businesses were destroyed and damage assessments exceeded three and a half million dollars.

A National Weather Service storm survey team confirmed an EF2 tornado that tracked from approximately three miles west of Arkdale to County Road G. The tornado caused extensive damage to barns, trees, and parts of a house two miles west of Arkdale. A cement silo was knocked over as well. The tornado crossed Highway 21 north of Arkdale hitting nearby homes, irrigation systems, and hundreds of trees. A very distinct convergent pattern was noted in the trees at this location with winds estimated around 125 mph. Several more farms, homes, and trees were hit as the tornado continued toward the south side of Big Roche A Cri Lake near the small community of Cottonville. Several cars and mobile homes were flipped or heavily damage. A lake association building on the southwest side of Big Roche A Cri Lake was completely destroyed and numerous center-pivot irrigation systems were twisted or destroyed across the county. EF2 damage was noted as the tornado widened to nearly a half mile wide. It crossed Highway 13 at Cottonville and gradually began to weaken hitting more seasonal homes, trees, and roof tops. The tornado dissipated south of the Colburn Wildlife area.

A National Weather Service storm survey team confirmed that a second tornado formed near County Road G and Buttercup Ave. north of where the Arkdale to Cottonville tornado dissipated. EF1 damage was noted to some homes and trees, especially along Buttercup Ave. as the tornado tracked into Waushara County. Several center-post irrigation systems were destroyed along with some roof damage to homes and power poles.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a tornado watch, issued at 20:22 UTC and running to 01:02 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:54 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The La Crosse radar (KARX), 115 km away, was scanning. The volume nearest the touchdown began at 23:14 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2011 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

15 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.