Tornadoes · United States · Minnesota · 2011

EF0 tornado, Forest Lake, Minnesota, May 22, 2011

This EF0 tornado ran 2.6 miles across Washington County on May 22, 2011, touching down at 3:16 PM CDT and reaching 75 yards wide. It killed nobody, and did $50,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. EF065 to 85 mphthis tornado

    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 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.

The record

Rating
EF0
Date
May 22, 2011
Touchdown
3:16 PM CDT (20:16 UTC)
Lifted
3:20 PM CDT (20:20 UTC)
On the ground
4 minutes
Path length
2.6 miles (4.2 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
Property damage
$50,000
County
Washington County
Touchdown point
45.237, -92.943
Lift-off point
45.272, -92.918
Record number
1105221416-01

What the Weather Service recorded

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.

An EF-0 tornado touched down near 200th Street and Imperial Avenue, or about three miles southeast of Forest Lake, Minnesota. It moved north-northeast, and dissipated on the north side of Forest Lake, near Shadeland Point. Damaged was confined to trees, roof shingles, and a large metal shed. The tornado was viewed by multiple spotters, chasers, law enforcement officers, and was seen on a MNDOT camera.

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

The warnings

6 minutes of warning. NWS MPX issued a tornado warning for this county at 20:10 UTC, 6 minutes before the tornado touched down, in force until 20:25 UTC.

The county was under a tornado watch, issued at 17:10 UTC and running to 21:08 UTC.

Issued (UTC)ExpiredProductOffice
17:10 UTC21:08 UTCTornado WatchMPX
19:45 UTC20:15 UTCTornado WarningMPX
20:10 UTC20:25 UTCTornado WarningMPX

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 forecast that day

The Storm Prediction Center had this point in a Slight Risk, with a 0.10 chance of a tornado within 25 miles. 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 air that afternoon

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, MN (KMPX), 12:00Z

8.3 hours before the tornado, 69 km from the path. May 22, 2011.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2011-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 20 joules per kilogram, CIN -103, lifted condensation level 981 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Minneapolis, MN at 12:00Z on 2011-05-22The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 207 square meters per square second, 0 to 6 km bulk shear 33 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
20 J/kg
Mixed-layer CIN
-103 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
981 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
207 m²/s²
0-3 km storm-relative helicity
243 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 00:00Z

3.7 hours after it, 69 km from the path. May 23, 2011.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2011-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 144 joules per kilogram, CIN -9, lifted condensation level 800 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Minneapolis, MN at 00:00Z on 2011-05-23The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 78 square meters per square second, 0 to 6 km bulk shear 36 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
144 J/kg
Mixed-layer CIN
-9 J/kg
Surface CAPE
1104 J/kg
Mixed-layer LCL
800 m above ground
0-6 km bulk shear
36 kt
0-1 km bulk shear
29 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The radar

The Minneapolis radar (KMPX), 67 km away, was scanning. The volume nearest the touchdown began at 20:14 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
19:15 UTCTORNADOMinneapolisHennepin, MN*** 1 FATAL, 30 INJ *** THE ONE FATALITY OCCURRED AT THE INTERSECTION OF 37TH AND FREMONT AVENUE NORTH. TWO PERSON WERE REPORTED CRITICALLY INJURED.12 PEOPLE HAD MODERATE INJURIES AND 15 HAD MINOR INJURIES.
19:16 UTCTORNADOMinneapolisHennepin, MNTREES DOWN 21ST AND THOMAS NORTH
19:16 UTCTORNADOSt Louis ParkHennepin, MNDEBRIS CLOUD HIGHWAY 100 AND 394..SURFACE LEVEL ROTATION
19:23 UTCTORNADOBrooklyn CenterHennepin, MNAT HIGHWAY 694 OVER MISSISSIPPI RIVER
19:27 UTCTORNADOMinneapolisHennepin, MN29TH AND LOGAN NORTH
19:30 UTCHAIL 1FridleyAnoka, MNALSO WIND DAMAGE TO GARDEN SHEDS AT HIGHWAY 100 AND 694
19:34 UTCTORNADOFridleyAnoka, MN51ST AND UNIVERSITY AVENUE...ROOF OFF HOUSE
19:37 UTCFUNNEL CLOUDSt PaulRamsey, MNSOUTH SIDE LAKE COMO
19:45 UTCTSTM WND DMGFridleyAnoka, MNCENTRAL AVE. AND 73RD ST 6 INCH TREE LIMBS DOWN
19:45 UTCTSTM WND DMGMinneapolisHennepin, MNFOLLOWUP REPORT...SOUTH OF 12TH AND UPTON EXTENSIVE TREE DAMAGE SOME STRUCTURE DAMAGE AS WELL...APPEARS TO BE WIND NOT TORNADO DAMAGE
19:47 UTCTSTM WND DMGMinneapolisHennepin, MN12 TO 18 INCH TREE LIMBS DOWN IN THEO. WIRTH PARK...SPOTTER SAYS POSIBLE TORNADO
19:52 UTCTORNADO2 Ese Ham LakeAnoka, MNRATED EF-0. PATH LENGTH 0.2 MILE. TREES DAMAGED.
20:06 UTCFUNNEL CLOUDN HugoWashington, MNWALL CLOUD WITH SIGNIFICANT ROTATION SEEMS TO BE DROPPING FUNNELS
20:16 UTCTORNADOS Forest LakeWashington, MNSOUTH OF FOREST LAKE NEAR JCT 35W AND 35E
20:19 UTCTORNADO3 Ese Forest LakeWashington, MN
20:20 UTCFUNNEL CLOUDCentervilleAnoka, MNROTATING WALL CLOUD 35E AND CR14
20:23 UTCFUNNEL CLOUD5 Ene Forest LakeChisago, MN
20:25 UTCTSTM WND DMG4 E Ham LakeAnoka, MN1-2 FT DIA TREES DOWN..FLAG POLE SNAPPED IN HALF. TRREES BLOWN DOWN IN DIRRERENT DIRECTIONS. NARROW DAMAGE PATH. POSSIBLE TORNADO
20:25 UTCTORNADO2 Wsw Chisago CityChisago, MNCAUGHT ON VIDEO NR CR36 AND IVYWOOD TRAIL
20:31 UTCTSTM WND DMGMinneapolisHennepin, MNTORNADO DAMAGE REPORT OF ROOFS AND SECOND STORIES OF HOUSES MISSING OR DAMAGED.
20:40 UTCTSTM WND DMGHam LakeAnoka, MNMEDIUM TO SMALL BRANCHES DOWN...SHINGLES BLOWN OFF ROOFS
20:42 UTCFUNNEL CLOUDLindstromChisago, MN
20:49 UTCTSTM WND DMGForest LakeWashington, MNTORNADO DAMAGE..POLE BARN AND HOUSE WITH EXTENSIVE DAMAGE

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2011 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of May 22, 2011

47 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 222:13 PM CDTEF1Hennepin, MN13.6880148$167 million
May 222:33 PM CDTEF1Price, WI to IA, MN3.3600$4,000
May 222:33 PM CDTEF2Howard, IA to MN28.72503$775,000
May 222:38 PM CDTEF0Lafayette, MO0.340$500
May 222:40 PM CDTEF2Iowa, IA3.975$250,000
May 222:52 PM CDTEF0Anoka, MN0.230$50,000
May 222:54 PM CDTEF0Iowa, IA2.025$10,000
May 223:13 PM CDTEF0Bremer, IA0.130
May 223:25 PM CDTEF0Lafayette, MO0.150
May 223:37 PM CDTEF1Fayette, IA7.970$175,000
May 223:58 PM CDTEF0Lafayette, MO0.150$3,000
May 224:00 PM CDTEF1Barron, WI2.0300$200,000
May 224:01 PM CDTEF0Fayette, IA1.450$10,000
May 224:05 PM CDTEF2Houston, MN to WI13.8150$15 million
May 224:10 PM CDTEF0Labette, KS0.350
May 224:37 PM CDTEF1Jasper, IN0.333$25,000
May 224:47 PM CDTEF1La Crosse, WI8.2125$920,000
May 224:50 PM CDTEF1Saline, MO3.575$230,000
May 225:15 PM CDTEF2Monroe, WI64.58001$7.7 million
May 225:34 PM CDTEF5Joplin tornado, MO21.61,6001581150$2.8 billion
May 225:39 PM CDTEF0Price, WI1.1350$1,000
May 225:52 PM CDTEF0Price, WI1.1400
May 226:01 PM CDTEF0Price, WI2.1350$5,000
May 226:10 PM CDTEF2Newton, MO14.1800$1.0 million
May 226:20 PM CDTEF0Jack, TX0.050
May 226:25 PM CDTEF1Ogle, IL29.1200$150,000
May 226:26 PM CDTEF0Price, WI0.8275
May 226:28 PM CDTEF1Ogle, IL1.7200$50,000
May 226:33 PM CDTEF2Delaware, OK6.7800$1.0 million
May 226:40 PM CDTEF1Ogle, IL0.5100$50,000
May 226:42 PM CDTEF1Wagoner, OK3.5300
May 226:52 PM CDTEF3Delaware, OK to MO17.91,5504$2.0 million
May 226:55 PM CDTEF1Winnebago, IL2.750
May 226:59 PM CDTEF1Winnebago, IL0.950$15,000
May 227:10 PM CDTEF2Stone, MO15.7200$1.1 million
May 227:27 PM CDTEF1Cherokee, OK3.0250$70,000
May 227:33 PM CDTEF0Green Lake, WI0.430$1,000
May 227:47 PM CDTEF0Green Lake, WI4.250$5,000
May 227:50 PM CDTEF0Cherokee, OK0.150
May 228:13 PM CDTEF1Delaware, OK4.7400$25,000
May 228:14 PM CDTEF2Adair, OK4.5200$250,000
May 228:29 PM CDTEF0Delaware, OK1.0100
May 228:30 PM CDTEF2Delaware, OK2.935012$400,000
May 228:36 PM CDTEF1Delaware, OK1.7150
May 228:41 PM CDTEF0Renville, ND0.125
May 228:44 PM CDTEF1Delaware, OK0.5100
May 228:54 PM CDTEF1Benton, AR2.8450$25,000

What this means

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.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.