EF2 tornado, Mound Prairie to Rockland, Minnesota, May 22, 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

May 22, 2011

Touchdown

4:05 PM CDT (21:05 UTC)

Lifted

4:28 PM CDT (21:28 UTC)

On the ground

23 minutes

Path length

13.8 miles (22.2 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

Property damage

$15 million

Counties

Houston and La Crosse counties

Touchdown point

43.741, -91.457

Lift-off point

43.798, -91.193

Record number

1105221505-01

During the afternoon of May 22nd, severe thunderstorms developed along a cold front as it moved through southeast Minnesota. These severe thunderstorms produced two confirmed tornadoes, both of which were rated as EF2. The first tornado moved into Fillmore County from northeast Iowa and the second tornado occurred over eastern Houston County before crossing the Mississippi River into western Wisconsin. The first tornado produced significant damage around Harmony (Fillmore County) where silos were damaged and roofs taken off structures. The second tornado produced damage around Hokah (Houston County) with barns and other farm buildings damaged along with several residences. Around 4,500 customers loss power across Fillmore and Houston Counties. Damages across southeast Minnesota were estimated to be between $400 and $500 thousand.

During the afternoon of May 22nd, severe thunderstorms developed along a cold front as it moved through western Wisconsin. These severe thunderstorms produced three confirmed tornadoes, two of which were rated as EF2 with the other being an EF1. The first tornado hit the southern sections of the city of La Crosse (La Crosse County) and caused an estimated 15 million dollars in damage where almost 200 buildings were damaged including 9 homes that were destroyed. The second tornado tracked from extreme eastern La Crosse County into Monroe County passing through the southern portions of Sparta (Monroe County). Considerable damage occurred in Sparta with a local car dealership sustaining damage to vehicles on the sales lot. The third tornado was on the ground for almost 65 miles as it tracked from eastern Monroe County, across northern Juneau County, through southern Wood County and into Portage County before dissipating. Damage estimates for this tornado in Monroe and Juneau Counties are close to 6 million dollars with most of this occurring in Juneau County where a cranberry farm was severely damaged.

This EF2 tornado cut a path across northeast Houston County from around 5 miles southwest of Hokah, through the very southern part of Hokah to the Target Lake area southeast of La Crescent, before crossing the Mississippi River. Near the beginning of the track, significant damage to some residences, barns and farm out buildings occurred. In the same area, numerous 100 foot tall and 3 foot diameter trees were either uprooted or snapped off. Around a mile west of Hokah, 2 barns were significantly damaged and a residence received minor damage. Some minor roof damage and extensive tree damage was done on the south side of the town of Hokah. Tree damage was noted east of Hokah into the Mississippi River. Damages from the tornado were estimated to be almost $250 thousand.

This tornado originally began in Houston County Minnesota and crossed into La Crosse near Target Lake. The first damage occurred on Green Island where numerous mature trees were snapped off and substantial damage occurred to the Green Island ice arena. The tornado then moved into a residential area where buildings sustained partial roof removal and garages were heavily damaged. Buildings in a small industrial area near the intersection of Green Bay Street and West Ave had walls partially collapse causing the roofs to subsequently collapse and a small apartment complex had its roof cleanly removed. After this, the tornado tracked primarily through residential areas until it dissipated causing mainly tree damage and light structural damage to homes and garages. An estimated 200 homes and businesses were damaged, 9 homes were destroyed and another 6 buildings condemned and uninhabitable. An emergency shelter was set up where up to 40 people sought refuge at times with 14 spending the night. This tornado was the first to hit the city of La Crosse since 1966 when a tornado moved across the airport. Total damages were estimated to be just over $15 million. An estimated 6,300 customers lost power as a result of the tornado. There was not a single ambulance call right after the tornado, but some did occur during the following days during clean up.

For the short time this tornado was in La Crosse County, it produced mainly tree and some minor building damage. The tornado tracked from just southwest of Rockland, toward the rest stop on the eastbound side of Interstate 90 before crossing into Monroe County.

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

19 minutes of warning. NWS ARX issued a tornado warning for this county at 20:46 UTC, 19 minutes before the tornado touched down, in force until 21:15 UTC.

The county was under a tornado watch, issued at 17:10 UTC and running to 22:30 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 20:00 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), 12 km away, was scanning. The volume nearest the touchdown began at 21:06 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 MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

47 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.