Tornadoes · United States · Minnesota · 2026

Unrated tornado, Stevens County, Minnesota, September 11, 2026

This Unrated tornado ran 1.0 miles across Stevens County on September 11, 2026, touching down at 7:44 PM CDT and reaching 45 yards wide. It killed nobody.

Preliminary. This is NWS MPX's damage survey, filed in the Damage Assessment Toolkit as StevensCo-SynnesTwp. The rating, the path and the casualties are the survey's and can change while it is revised. The Storm Prediction Center compiles the official record of 2026 from these surveys and publishes it in the spring of 2027; this page moves to that tornado's permanent address when it does.

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 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. Unratedthis tornado

    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 survey

Rating, as surveyed
Unrated, preliminary
Date
September 11, 2026
Touchdown
7:44 PM CDT (00:44 UTC)
Lifted
7:48 PM CDT (00:48 UTC)
On the ground
4 minutes
Path length
1.0 miles (1.7 km)
Path width
45 yards (41 m)
Deaths
0
Injuries
0
County
Stevens County
Touchdown point
45.457, -96.117
Lift-off point
45.459, -96.095
Surveyed by
NWS MPX
The office's name for it
StevensCo-SynnesTwp
Survey last edited
September 16, 2026
Record number
None yet. SPC numbers 2026 in the spring of 2027.

What the survey found

Numerous storm spotters and chasers viewed this tornado as it travelled across corn and bean fields. Video showed this to be a multiple vortex tornado, and damage to corn stalks showed this as well. No structures were impacted and no damage indicators hit. Therefore the tornado has been given a rating of EFU. Extremely thorough survey information was provided by Stevens County Emergency Management.

Written by NWS MPX in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.

The damage survey

3 damage points were recorded along this path by NWS MPX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EFU. The highest wind the damage implies is 98 mph.

  • Corn damage at beginning of tornado path. Photo by Stevens County Emergency Management..
  • End of tornado with matted grass. Photo by Stevens County Emergency Management.
  • Six power poles were snapped approximately two feet off the ground. Photo by Stevens County Emergency Management.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 23:40 UTC and running to 03:00 UTC.

Issued (UTC)ExpiredProductOffice
23:40 UTC03:00 UTCSevere Thunderstorm WatchMPX
23:51 UTC00:45 UTCSevere Thunderstorm WarningMPX
00:41 UTC01:19 UTCSevere Thunderstorm WarningMPX
00:46 UTC01:09 UTCTornado WarningMPX
01:04 UTC01:22 UTCTornado WarningMPX
01:32 UTC01:48 UTCSevere Thunderstorm 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 0.02 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.

Aberdeen, SD (KABR), 00:00Z

0.7 hours before the tornado, 190 km from the path. September 12, 2026.

Skew-T log-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 2026-09-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1015 joules per kilogram, CIN -122, lifted condensation level 1133 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Aberdeen, SD at 00:00Z on 2026-09-12The 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 -85 square meters per square second, 0 to 6 km bulk shear 35 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
1015 J/kg
Mixed-layer CIN
-122 J/kg
Surface CAPE
1951 J/kg
Mixed-layer LCL
1133 m above ground
0-6 km bulk shear
35 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
-85 m²/s²
0-3 km storm-relative helicity
-56 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1
0-3 km lapse rate
6.2 K/km

Open this sounding in Storm Lab

The radar

The Aberdeen radar (KABR), 180 km away, was scanning. The volume nearest the touchdown began at 00:44 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
23:29 UTCHAIL 17 Ne DumontTraverse, MNhail increasing in size at time of the report.
23:37 UTCHAIL 1.257 Ne DumontTraverse, MN
23:38 UTCHAIL 1.254.8 Sw HermanGrant, MN
23:47 UTCHAIL 1.252 Sse NorcrossGrant, MN
00:30 UTCTSTM WND DMGChokioStevens, MNPower outage in Chokio due to tree branches on power lines.
00:30 UTCHAIL 1ChokioStevens, MN
00:38 UTCHAIL 1.256 S AlbertaStevens, MNReport from mPING: Half Dollar (1.25 in.).
00:40 UTCHAIL 17 Ne ArtichokeStevens, MNReport from mPING: Quarter (1.00 in.).
00:44 UTCTORNADO4 Ne ArtichokeStevens, MNInitial touchdown, corrects location from previous report. Trained spotter confirmed brief tornado touchdown in an open field, with sporadic damage to crops along a patch that was slightly more than 1 mile off to the nor
00:50 UTCNON-TSTM WND DMG8 S AlbertaStevens, MN8 power poles blocking county highway 9 near Trinity Lutheran Cemetery, likely caused by severe winds from the rear flank downdraft.
00:50 UTCTORNADO8 S AlbertaStevens, MN8 power poles blocking county highway 9 near Trinity Lutheran Cemetery.
00:51 UTCTORNADO7 Ne ArtichokeStevens, MNTornado touchdown reported 7 miles northeast of Artichoke. Location estimated.
00:53 UTCHAIL 1.755 E ArtichokeStevens, MNReport from mPING: Golf Ball (1.75 in.).
00:54 UTCHAIL 1.757 S AlbertaStevens, MNGolf ball sized hail 8 miles northeast of Artichoke MN reported by Trained Spotter.
01:28 UTCHAIL 1.57 S AlbertaStevens, MN
01:30 UTCHAIL 1.757 S AlbertaStevens, MN

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

This ground now

The live radar over the trackEvery 2026 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota 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. A survey can be revised, so the rating, the path and the casualties can all still change.

Sources

NWS Damage Assessment Toolkit, the record the survey teams file from the damage, and NOAA Storm Prediction Center storm reports. Neither is the official database for 2026, which SPC publishes in the spring of 2027.