EF2 tornado, Spokeville to Chili, Wisconsin, August 23, 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

August 23, 2011

Touchdown

5:05 PM CDT (22:05 UTC)

Lifted

5:30 PM CDT (22:30 UTC)

On the ground

25 minutes

Path length

7.6 miles (12.2 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

2

Property damage

$1.4 million

Crop damage

$90,700

County

Clark County

Touchdown point

44.688, -90.471

Lift-off point

44.669, -90.318

Record number

1108231605-01

Two people were directly injured and an indirect death occurred from an EF2 tornado near Chili (Clark County) during the late afternoon of August 23rd. The death occurred when an oxygen machine stopped working due to a power outage caused by the tornado. The tornado destroyed four homes, damaged close to 20 others and destroyed numerous farm buildings. Damages from the tornado are estimated to be around $1.5 million.

Two people were directly injured and there was an indirect loss of life from an EF2 tornado that tracked across the east central sections of Clark County near Chili. The death occurred when an oxygen machine stopped working due to a power outage caused by the tornado. The tornado was on the ground for just over 7 miles and destroyed four homes, damaged at least 19 others, destroyed four barns and 15 outbuildings with numerous other farm buildings damaged. One farmer lost several specialty birds including 12 peacocks and 16 guinea hens. Around 1500 residents across Clark County were without power after the storms moved through. Damages from the tornado are estimated to be around $1.5 million.

The deaths

0 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

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.

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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:03 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), 114 km away, was scanning. The volume nearest the touchdown began at 22:02 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

3 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.