Tornadoes · United States · Michigan · 2021

EF1 tornado, Bankers to Steamburg, Michigan, September 7, 2021

From Bankers to Steamburg, this EF1 tornado ran 5.3 miles across Hillsdale County on September 7, 2021, touching down at 7:45 PM EDT and reaching 450 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 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.

The record

Rating
EF1
Date
September 7, 2021
Touchdown
7:45 PM EDT (23:45 UTC)
Lifted
7:51 PM EDT (23:51 UTC)
On the ground
6 minutes
Path length
5.3 miles (8.6 km)
Path width
450 yards (411 m)
Deaths
0
Injuries
0
County
Hillsdale County
Touchdown point
41.898, -84.693
Lift-off point
41.893, -84.590
Record number
2109071745-01

What the Weather Service recorded

A line of storms moved through southern MI well ahead of a cold front. These storms produced flooding rains over northern Berrien (training), and locally damaging wind gusts and small hail from Berrien County to Hillsdale County. There was also an EF1 tornado in Hillsdale County.

A weak tornado developed west of the intersection of S Bunn Road and Cole/Bankers Road, and moved quickly east along the north side of the road causing areas of significant tree damage east to Cambria Road. Two 1000 lb round hay bales were picked up from a field south of Bankers Road and thrown into a ditch and yard on the north side of the road. Several power poles were snapped in the area. It appears the tornado briefly lifted after crossing Cambria Road, but touched down again on the east side of S Hillsdale Road where several outbuildings and a silo were destroyed. The tornado intensified further as it moved through the Hillsdale Golf and Country Club where considerable, widespread tree damage, including several uprooted trees, occurred. The tornado quickly weakened as it moved across Baw Beese Lake with a few tree branches damaged along Oakwood Drive. No further damage was observed past this point. Maximum winds estimated at around 100 mph (EF-1) with a maximum width of around 450 yards.

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.

The county was under a severe thunderstorm watch, issued at 19:20 UTC and running to 00:30 UTC.

Issued (UTC)ExpiredProductOffice
19:20 UTC00:30 UTCSevere Thunderstorm WatchIWX
23:46 UTC00:15 UTCSevere Thunderstorm WarningIWX

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 19:45 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.

Detroit, MI (KDTX), 12:00Z

11.8 hours before the tornado, 135 km from the path. September 7, 2021.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 12:00Z on 2021-09-07Temperature 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 -80515, lifted condensation level 1621 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Detroit, MI at 12:00Z on 2021-09-07The 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 150 square meters per square second, 0 to 6 km bulk shear 32 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
-80515 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1621 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.1 K/km

Open this sounding in Storm Lab

The surface observations

Hillsdale (JYM), 5 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:55 UTC79.358.3200° 10 kt161006.1
22:15 UTC78.458.6190° 8 kt1006.4
22:35 UTC78.358.8220° 6 kt1006.8
22:55 UTC7858.6200° 5 kt1006.4
23:15 UTC7362.4190° 7 kt1006.4RA
23:35 UTC7064.40° 0 kt1006.1-RA
23:55 UTC6965.7330° 24 kt321007.8RA
00:15 UTC65.363290° 11 kt161008.5-RA
00:35 UTC64.262.60° 0 kt1007.8
00:55 UTC64.4620° 0 kt1007.1
01:15 UTC63.5620° 0 kt1006.8
01:35 UTC6462.6300° 8 kt1007.8RA

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

The radar

The Northern Indiana radar (KIWX), 106 km away, was scanning. The volume nearest the touchdown began at 23:47 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
22:05 UTCTSTM WND DMG2 Sse SpringportJackson, MITREE DOWN AT GIBBS ROAD AND TOWN ROAD.
22:25 UTCTSTM WND DMG6 Ne JacksonJackson, MISEVERAL REPORTS OF TREES DOWN IN LEONI TOWNSHIP ESPECIALLY AT HAWKINS ROAD AND DALTON ROAD.
23:40 UTCTSTM WND DMGAllenHillsdale, MISEVERAL LARGE TREES DOWN OVER THE ROAD. VIA SPOTTER NETWORK. TIMES ESTIMATED FROM RADAR.
23:46 UTCTSTM WND DMGAllenHillsdale, MITREES AND POWER POLES/LINES DOWNED.
23:47 UTCTSTM WND DMG2 Nne Lake WilsonHillsdale, MITREES DOWN BLOCKING THE ROAD. LOCATION IS APPROXIMATE. TIME ESTIMATED FROM RADAR.
23:47 UTCTSTM WND DMGHillsdaleHillsdale, MITREES DOWNED, SOME ONTO BUILDINGS. POWER LINES AND POLES DOWNED.
23:55 UTCTSTM WND DMGOsseoHillsdale, MIROOF BLOWN OFF HOUSE. POLE BARN AND FARM SILO DESTROYED.
00:04 UTCTSTM WND DMG3 Nne HudsonLenawee, MIDISPATCH REPORTS LARGE BRANCHES AND POWER LINES DOWN IN THE CITIES OF ADDISON AND HUDSON.

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

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.