EF1 tornado, St Louis Park to Ham Lake, 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 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 22, 2011

Touchdown

2:13 PM CDT (19:13 UTC)

Lifted

2:34 PM CDT (19:34 UTC)

On the ground

21 minutes

Path length

13.6 miles (21.8 km)

Path width

880 yards (805 m)

Deaths

1

Injuries

48

Property damage

$167 million

Counties

Hennepin, Ramsey and Anoka counties

Touchdown point

44.960, -93.347

Lift-off point

45.132, -93.214

Record number

1105221313-01

During the early afternoon of Sunday May 22nd, a line of thunderstorms developed across south central Minnesota, and quickly moved north and northeast across east-central Minnesota, and into west-central Wisconsin. One spawned a tornado in North Minneapolis, and crossed into southern Anoka County. Another tornado occurred near Ham Lake, and another near Forest Lake that afternoon.

A strong EF-1 tornado touched down approximately 3/4 of a mile south-southwest of the intersection of Interstate 394 and Highway 100 in St. Louis Park, Minnesota. It traveled north-northeast through Golden Valley, and across North Minneapolis, before moving into Anoka County. ||Damage was widespread along the path and caused damage to businesses near the intersection of Interstate 394, and Highway 100. As it crossed Highway 100, it began to damage numerous residences along Cedar Lake Road before moving into Theodore Wirth Park. The tornado moved across Wirth Park, and into the City of North Minneapolis, between Glenwood Avenue and 16th Avenue. ||Most of the damage at this point was EF-0 and was confined to downed trees and roof damage. It strengthened to EF-1 as it moved into North Minneapolis. The tornado tracked across Penn Avenue and Broadway, then to Lowry Avenue and Logan Avenue, then to 42nd Avenue to Lyndale Avenue before crossing the Mississippi River. Damage along this path was extensive to garages, with sheds and roofs removed.||A male was killed as a tree fell on his car while he was driving in North Minneapolis. City officials stated that more than 600 buildings would require major repairs, and 35 homes were so badly damaged they could not be reoccupied.

An EF-1 tornado continued into Anoka County from the Camden Bridge along the Mississippi River, north-northeast to the east side of Fridley, to Spring Lake where it moved into Ramsey County. ||Damage was extensive along the path where it moved into a rail yard and a large industrial facility. A large metal building roof was ripped off in the industrial area, and eight train cars were tipped over where EF-1 damage was observed. Several warehouses sustained damaged along Miami Street where a roof was blown off. ||The tornado then moved across residential sections of Fridley, before it weakened as it continued northeast across the east side of Fridley, near Spring Lake. Damage was confined to trees blown down along the path, then moved into Ramsey County.

An EF-0 tornado continued in Ramsey County, near Spring Lake, then north-northeast as it crossed back into Anoka County, near Highway 10, south of the Blaine-Anoka County Airport. Most of the damage was confined to sporadic trees blown down along the path.

An EF-0 continued into Anoka County, and dissipated on the south side of the Blaine-Anoka County Airport. Damage was confined to several hangers on the airport grounds, that had their exterior walls damaged.

An EF-0 tornado briefly touched down near 155th Street Northeast, and County Highway 17 east of Ham Lake. Damage was confined to trees blown down and a few shingles ripped off homes.

The deaths

1 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.

3 minutes of warning. NWS MPX issued a tornado warning for this county at 19:10 UTC, 3 minutes before the tornado touched down, in force until 19:45 UTC.

The county was under a tornado watch, issued at 17:10 UTC and running to 21:08 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:18 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.

Minneapolis - Crystal (MIC), 6 km from the path, in the two hours either side.

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

The Minneapolis radar (KMPX), 31 km away, was scanning. The volume nearest the touchdown began at 19:14 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 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.