Tornadoes · United States · Michigan · 2021

EF0 tornado, Munnscong to Neebish, Michigan, August 11, 2021

From Munnscong to Neebish, this EF0 tornado ran 1.5 miles across Chippewa County on August 11, 2021, touching down at 4:04 PM EDT and reaching 75 yards wide. It killed nobody.

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
August 11, 2021
Touchdown
4:04 PM EDT (20:04 UTC)
Lifted
4:08 PM EDT (20:08 UTC)
On the ground
4 minutes
Path length
1.5 miles (2.4 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
County
Chippewa County
Touchdown point
46.238, -84.164
Lift-off point
46.236, -84.133
Record number
2108111404-01

What the Weather Service recorded

A seasonably strong shortwave rotated over the Great Lakes to produce a second round of severe thunderstorms across all of northern Michigan during the afternoon and evening of 8/11. The strongest storms tracked over and east of Kinross, MI and over the M-32 corridor from the Gaylord area into Alpena.

A brief EF-0 tornado was analyzed in satellite imagery by the Northern Tornadoes Project of Canada. Damage was limited to trees on Neebish Island.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Issued (UTC)ExpiredProductOffice
19:47 UTC20:30 UTCSevere Thunderstorm WarningAPX
20:11 UTC21:00 UTCSevere Thunderstorm WarningAPX

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 0.02 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 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.

Alpena, MI (KAPX), 12:00Z

8.1 hours before the tornado, 188 km from the path. August 11, 2021.

Skew-T log-pSkew-T log-p diagram, Alpena, MI at 12:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2 joules per kilogram, CIN -340, lifted condensation level 1366 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, Alpena, MI at 12:00Z on 2021-08-11The 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 158 square meters per square second, 0 to 6 km bulk shear 27 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
2 J/kg
Mixed-layer CIN
-340 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1366 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.9 K/km

Open this sounding in Storm Lab

Alpena, MI (KAPX), 00:00Z

3.9 hours after it, 188 km from the path. August 12, 2021.

Skew-T log-pSkew-T log-p diagram, Alpena, MI at 00:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -334, lifted condensation level 1894 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, Alpena, MI at 00:00Z on 2021-08-12The 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 335 square meters per square second, 0 to 6 km bulk shear 44 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
0 J/kg
Mixed-layer CIN
-334 J/kg
Surface CAPE
64 J/kg
Mixed-layer LCL
1894 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
41 kt
0-1 km storm-relative helicity
335 m²/s²
0-3 km storm-relative helicity
507 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

The radar

The NCL Michigan radar (KAPX), 155 km away, was scanning. The volume nearest the touchdown began at 20:04 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
19:48 UTCTSTM WND GST 441 Nnw Sault Ste. MarieChippewa, MIBUOY STATION SWPM4 S.W. PIER, MI.
19:49 UTCTSTM WND GST 641 Sse KinrossChippewa, MIAWOS STATION KCIU KINROSS - CHIPPEWA COUNTY INTERNATIONAL ARPT.
19:50 UTCTSTM WND DMG4 Ssw DonaldsonChippewa, MI*** 1 INJ *** DRONE PICTURES SHOW NUMEROUS TREES DOWN ABOUT 1/4 WEST OF M-129 ON M-80.
19:50 UTCTSTM WND GST 521 Sw KincheloeChippewa, MIMESONET STATION RYDM4 RUDYARD.
19:55 UTCTSTM WND DMGPickfordChippewa, MISOCIAL MEDIA REPORTS W/ PICTURES SHOWING HOUSE SIDING AND HORSE SHELTER ROOF BLOWN OFF.
20:00 UTCTSTM WND DMG2 Ese MunuscongChippewa, MIDELAYED REPORT. DRONE FOOTAGE SENT IN ON SOCIAL MEDIA.
20:06 UTCTSTM WND GST 603 Nnw MunuscongLsz322, MIBUOY STATION WNEM4 WEST NEEBISH ISLAND, MI.
20:14 UTCTSTM WND GST 521 Sw KincheloeChippewa, MIMESONET STATION RYDM4 RUDYARD.

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

This ground now

The live radar over the trackEvery 2021 tornado in MichiganEvery tornado in Michigan since 1950Warnings in force in Michigan nowThe forecast where you are

The other tornadoes of August 11, 2021

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 112:40 PM EDTEF1Fulton, OH0.270
August 111:45 PM CDTEF1Monroe, WI5.980$40,000
August 112:49 PM EDTUnratedVan Wert, OH2.030
August 111:55 PM CDTEF1Monroe, WI2.875$3,000
August 113:00 PM EDTEF0Van Wert, OH4.750
August 112:08 PM CDTEF0Shawano, WI0.441
August 112:14 PM CDTEF0Brown, WI2.375
August 115:40 PM CDTEF0Dubuque, IA0.620
August 116:08 PM CDTEF0Iowa, WI0.125
August 116:12 PM CDTEF0Iowa, WI1.025
August 119:01 PM EDTEF0Allegan, MI2.8100$300,000

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.