Tornadoes · United States · Minnesota · 2021

EF0 tornado, Clinton to Barry, Minnesota, October 13, 2021

From Clinton to Barry, this EF0 tornado ran 0.0 miles across Big Stone County on October 13, 2021, touching down at 3:46 PM CDT and reaching 10 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
October 13, 2021
Touchdown
3:46 PM CDT (20:46 UTC)
Lifted
3:47 PM CDT (20:47 UTC)
On the ground
1 minutes
Path length
0.0 miles (0.1 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Big Stone County
Touchdown point
45.500, -96.560
Lift-off point
45.500, -96.559
Record number
2110131446-01

What the Weather Service recorded

A line of October thunderstorms along a front produced rare tornadoes in west central Minnesota during the afternoon hours resulting in damage.

The Graceville, MN Fire Department observed a tornado.

A tornado was photographed south of Barry.

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. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
20:50 UTC21:30 UTCTornado WarningABR

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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:55 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), 12:00Z

8.8 hours before the tornado, 159 km from the path. October 13, 2021.

Skew-T log-pSkew-T log-p diagram, Aberdeen, SD at 12:00Z on 2021-10-13Temperature 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 -55268, lifted condensation level 913 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, Aberdeen, SD at 12:00Z on 2021-10-13The 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 252 square meters per square second, 0 to 6 km bulk shear 62 knots.1939587897Sfc1 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
-55268 J/kg
Surface CAPE
1 J/kg
Mixed-layer LCL
913 m above ground
0-6 km bulk shear
62 kt
0-1 km bulk shear
31 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
334 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

Aberdeen, SD (KABR), 00:00Z

3.2 hours after it, 159 km from the path. October 14, 2021.

Skew-T log-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 2021-10-14Temperature 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 -88873, lifted condensation level 698 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, Aberdeen, SD at 00:00Z on 2021-10-14The 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 188 square meters per square second, 0 to 6 km bulk shear 37 knots.1939587897Sfc1 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
-88873 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
698 m above ground
0-6 km bulk shear
37 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
188 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.8 K/km

Open this sounding in Storm Lab

The surface observations

Ortonville (VVV), 24 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:55 UTC60.855.4140° 22 kt28993.2
19:15 UTC60.857.2140° 21 kt29992.6
19:35 UTC62.657.2130° 18 kt27991.9
19:55 UTC62.657.2130° 19 kt25991.2
20:15 UTC62.657.2130° 22 kt31990.5VCTS
20:35 UTC60.853.6200° 19 kt28991.9+VCTSRA
20:55 UTC57.248.2210° 18 kt28991.9
21:15 UTC57.246.4190° 15 kt28992.2VCTS
21:35 UTC57.244.6190° 19 kt28992.9
21:55 UTC55.442.8190° 16 kt28993.2
22:15 UTC55.442.8190° 18 kt26993.6
22:35 UTC55.442.8190° 17 kt26993.9

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

The radar

The Aberdeen radar (KABR), 145 km away, was scanning. The volume nearest the touchdown began at 20:44 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
20:30 UTCTORNADO9 Nw Big Stone CityRoberts, SDA SMALL WATERSPOUT TRACKED ACROSS BIG STONE LAKE. APPROXIMATE LOCATION BASED ON REPORT AND RADAR.
20:33 UTCTORNADO3 N OdessaBig Stone, MNTORNADO OBSERVED WITH PHOTO. TIME APPROXIMATED FROM RADAR.
20:42 UTCTORNADO4 Nw ClintonBig Stone, MNCONFIRMED BY GRACEVILLE FIRE DEPARTMENT. TIME APPROXIMATED BASED ON RADAR.
20:46 UTCTORNADO4 S BarryBig Stone, MNCONFIRMED WITH PICTURES SENT VIA SOCIAL MEDIA.
21:18 UTCTORNADO9 Nnw WheatonTraverse, MNDAMAGE TO TREES, A POLE BARN, AND FARM EQUIPMENT. SEE OFFICIAL NWS DAMAGE SURVEY FOR MORE INFORMATION.
21:22 UTCTORNADO9 Ne DumontTraverse, MNCORRECTS PREVIOUS TSTM WND DMG REPORT FROM 9 NE DUMONT. UPROOTED TREE AND ROOF OFF AN OUTBUILDING, REPORTED BY TRAVERSE COUNTY SHERIFF. SEE PNS FOR NWS SURVEY INFORMATION.
21:23 UTCTSTM WND DMG9 Ne DumontTraverse, MNUPROOTED TREE AND ROOF OFF AN OUTBUILDING, REPORTED BY TRAVERSE COUNTY SHERIFF. POTENTIAL TORNADO. RADAR APPROXIMATED TIME.

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 MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of October 13, 2021

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 134:59 AM CDTEF1Canadian, OK6.4150$50,000
October 135:15 AM CDTEF1Oklahoma, OK3.375$20,000
October 135:22 AM CDTEF0Oklahoma, OK4.250$1,000
October 131:15 PM CDTEF0Sully, SD0.210
October 133:03 PM CDTEF0Roberts, SD2.410
October 133:25 PM CDTEF0Roberts, SD0.110
October 133:30 PM CDTEF0Roberts, SD0.110
October 133:33 PM CDTEF0Big Stone, MN0.110
October 133:42 PM CDTEF0Big Stone, MN0.310
October 134:04 PM CDTEF0Sargent, ND5.425
October 134:18 PM CDTEF1Traverse, MN2.820
October 134:20 PM CDTEF0Traverse, MN0.410

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.