F1 tornado, De Graff to Willmar, Minnesota, June 11, 2001

1. F040 to 72 mph

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

2. F173 to 112 mphthis tornado

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

3. F2113 to 157 mph

   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. F3158 to 206 mph

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

5. F4207 to 260 mph

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

6. F5261 to 318 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

F1

Date

June 11, 2001

Touchdown

3:27 PM CDT (20:27 UTC)

Path length

7.0 miles (11.3 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Counties

Swift and Kandiyohi counties

Touchdown point

45.330, -95.320

Lift-off point

45.300, -94.170

Record number

972

Brief tornado over open land tracked east and crossed Highway 212 before dissipating.

After several brief tornadoes around Danvers, a much larger tornado struck the east side of Benson and travelled southeast along Highway 212. 71 structures were damaged, including 4 homes and 7 businesses that had to be demolished. The tornado lifted off in DeGraff, but not before damaging one last grain bin, taking the roof off a grain elevator, and knocking several sheds down in DeGraff. Seven people were injured when they fled a van just as the tornado was hitting the vehicle on the eastern edge of Benson. One boy was critically injured but survived and was discharged from the hospital two weeks later. Damage listed encompasses damages from all tornadoes and wind events in Swift County.

A new mesocyclone formed to the northeast of the storm that produced the Benson tornado. This new storm went on to produce five tornadoes, with the last one occurring near New Market in Scott County. This storm also produced large hail and very strong damaging wind from its beginning, all the way to the southern suburbs of Minneapolis. This mesocyclones first tornado touched down in Swift County, 9 N to NNE Kerkhoven, and knocked down two barns and several outbuildings in the Monson Lake area before traveling into Kandiyohi County, one mile southwest of Sunburg.

Tornado entered Kandiyohi County after forming 9 NNE Kerkhoven in Swift County. It traveled southeast, demolishing several barns, grain bins and outbuildings.

Tornado knocked down a few dozen trees.

Several barns and outbuildings down, church lost its roof, then tornado dissipated over open land. Filmed by storm chaser.

Sheds and pole barns down. Church lost part of its roof. Two people were injured when their truck and camper were flung to the edge of a lake.

This was the last tornado associated with the complex that produced the Benson F2 tornado. The storm had travelled along Highway 212 from Danvers to Benson to Kandiyohi, producing numerous tornadoes, hail, and strong wind gusts.

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

45 minutes of warning. NWS MPX issued a tornado warning for this county at 19:42 UTC, 45 minutes before the tornado touched down, in force until 20:30 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. The outlook in force was issued at 20:24 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.

Litchfield (LJF), 31 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The live radar over the trackEvery 2001 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

29 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.