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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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) | Expired | Product | Office |
|---|---|---|---|
| 23:40 UTC | 03:00 UTC | Severe Thunderstorm Watch | MPX |
| 23:51 UTC | 00:45 UTC | Severe Thunderstorm Warning | MPX |
| 00:41 UTC | 01:19 UTC | Severe Thunderstorm Warning | MPX |
| 00:46 UTC | 01:09 UTC | Tornado Warning | MPX |
| 01:04 UTC | 01:22 UTC | Tornado Warning | MPX |
| 01:32 UTC | 01:48 UTC | Severe Thunderstorm Warning | MPX |
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.
- 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
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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 23:29 UTC | HAIL 1 | 7 Ne Dumont | Traverse, MN | hail increasing in size at time of the report. |
| 23:37 UTC | HAIL 1.25 | 7 Ne Dumont | Traverse, MN | |
| 23:38 UTC | HAIL 1.25 | 4.8 Sw Herman | Grant, MN | |
| 23:47 UTC | HAIL 1.25 | 2 Sse Norcross | Grant, MN | |
| 00:30 UTC | TSTM WND DMG | Chokio | Stevens, MN | Power outage in Chokio due to tree branches on power lines. |
| 00:30 UTC | HAIL 1 | Chokio | Stevens, MN | |
| 00:38 UTC | HAIL 1.25 | 6 S Alberta | Stevens, MN | Report from mPING: Half Dollar (1.25 in.). |
| 00:40 UTC | HAIL 1 | 7 Ne Artichoke | Stevens, MN | Report from mPING: Quarter (1.00 in.). |
| 00:44 UTC | TORNADO | 4 Ne Artichoke | Stevens, MN | Initial 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 UTC | NON-TSTM WND DMG | 8 S Alberta | Stevens, MN | 8 power poles blocking county highway 9 near Trinity Lutheran Cemetery, likely caused by severe winds from the rear flank downdraft. |
| 00:50 UTC | TORNADO | 8 S Alberta | Stevens, MN | 8 power poles blocking county highway 9 near Trinity Lutheran Cemetery. |
| 00:51 UTC | TORNADO | 7 Ne Artichoke | Stevens, MN | Tornado touchdown reported 7 miles northeast of Artichoke. Location estimated. |
| 00:53 UTC | HAIL 1.75 | 5 E Artichoke | Stevens, MN | Report from mPING: Golf Ball (1.75 in.). |
| 00:54 UTC | HAIL 1.75 | 7 S Alberta | Stevens, MN | Golf ball sized hail 8 miles northeast of Artichoke MN reported by Trained Spotter. |
| 01:28 UTC | HAIL 1.5 | 7 S Alberta | Stevens, MN | |
| 01:30 UTC | HAIL 1.75 | 7 S Alberta | Stevens, 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.