EF1 tornado, Clarissa, Minnesota, May 12, 2022

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 mphthis tornado

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

3. EF2111 to 135 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. 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

EF1

Date

May 12, 2022

Touchdown

7:33 PM CDT (00:33 UTC)

Lifted

7:36 PM CDT (00:36 UTC)

On the ground

3 minutes

Path length

3.3 miles (5.3 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

County

Todd County

Touchdown point

46.105, -94.963

Lift-off point

46.147, -94.931

Record number

2205121833-01

12 damage points were recorded along this path by NWS MPX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

• start of tornado that went into Wadena County

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A line of severe thunderstorms that developed across South Dakota and Nebraska during the afternoon of Thursday, May 12th, was a classic bow echo that surged north and east across western Minnesota. ||Temperatures in the mid to upper 90s along with dew points in the mid to upper 60s created ample instability for thunderstorms to develop ahead of a cold front, once the cap weakened during the evening. Despite fairly muggy dew points, the hot surface temperatures created inverted-V soundings that were primed for damaging wind potential. Thunderstorms came in three waves during the evening, as marginal shear values prohibited any long-lived or well-organized thunderstorms across the area.||Winds were measured by wind sensors at over 100 mph across portions of South Dakota, with a measured wind gust at Madison, Minnesota of 94 mph. There were also numerous measured wind gusts between 60 and 80 mph across west central and southwest Minnesota with embedded surges that produced a few tornadoes. The most concentrated area of damage based on reports of farm equipment, trailers, semis, trees, power lines, and other debris, occurred near the upper Minnesota River Valley, northward to Alexandria and Long Prairie.||Over Stevens County alone, structural damage was considerable as the majority of the damage was to farm outbuildings, sheds and grain bins. There were a few locations in the county where the main inhabited house or home structure did suffer loss of roof and siding and windows but those were more isolated in nature. Many locations had debris tossed a mile northeast from its parent location. Nearly 100% of the damage witnessed in Stevens county was consistent with a straight line wind event, with just one tornado crossing the southeast corner of the county. ||Ten tornadoes were confirmed this day, with two in Lac Qui Parle County, including a house in Bellingham that had much of its roof removed. In northwestern Swift County, a tornado tipped over trailers and various farm equipment was heavily damaged. Two tornadoes were in Todd County, including one that moved through Clarissa. Two more were in Morrison County, and one was on the east side of Lake Alexander, where many trees came down on vehicles, sheds, and cabins. A tornado also occurred in Douglas County, on the northwest side of Alexandria, where EF2 damage was noted. The ninth tornado touched down south of Lowry in Pope County and was caught on video, and the tenth was in northwestern Stearns County, affecting the north side of Sauk Centre, and it was also caught on video.

Hundreds of trees were uprooted or broken. Several outbuildings lost roofs. The damage pattern in this part of Todd County was very complicated, but ground and aerial surveys revealed a tornado moved through part of Clarissa. Maximum winds were estimated at 90 mph.

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

1 minute of warning. NWS MPX issued a tornado warning for this county at 00:32 UTC, 1 minute before the tornado touched down, in force until 00:45 UTC.

The county was under a tornado watch, issued at 22:35 UTC and running to 03:34 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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 19:59 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 Minneapolis radar (KMPX), 178 km away, was scanning. The volume nearest the touchdown began at 00:32 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 2022 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

31 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.