Tornadoes · United States · Minnesota · 2021

EF0 tornado, Farming to Albany, Minnesota, August 28, 2021

From Farming to Albany, this EF0 tornado ran 2.1 miles across Stearns County on August 28, 2021, touching down at 11:26 AM CDT and reaching 25 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 28, 2021
Touchdown
11:26 AM CDT (16:26 UTC)
Lifted
11:28 AM CDT (16:28 UTC)
On the ground
2 minutes
Path length
2.1 miles (3.3 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Stearns County
Touchdown point
45.573, -94.599
Lift-off point
45.576, -94.557
Record number
2108281026-01

What the Weather Service recorded

Severe thunderstorms that developed across South Dakota early Saturday morning, August 28th, quickly moved into west central Minnesota and produced up to 3 diameter hail in Swift County. These storms congealed into a fast moving bow-echo that surged across parts of central Minnesota, between Willmar, St. Cloud and Mora. Several areas received very large hail, severe wind gusts and straight-line winds, and there was one tornado south of Albany. As the storms moved over east-central Minnesota, the severity of the storms lessened and only produced isolated wind damage around Milaca. The worst damaged areas were near Glenwood, Sauk Centre, and north and east of St. Cloud where numerous trees were blown down.

A storm chaser reported a brief tornado, and so a storm survey was conducted. The tornado tracked mostly across fields, but it did damage about two dozen trees, some of which were knocked over. The tornado was not always strong enough to produce corn and tree damage, but it did so occasionally along its path. The storm chaser took drone video a few days later, also revealing the tornado path.

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

The warnings

2 minutes of warning. NWS MPX issued a tornado warning for this county at 16:24 UTC, 2 minutes before the tornado touched down, in force until 17:00 UTC.

The county was under a severe thunderstorm watch, issued at 12:10 UTC and running to 17:00 UTC.

Issued (UTC)ExpiredProductOffice
12:10 UTC17:00 UTCSevere Thunderstorm WatchMPX
15:41 UTC16:30 UTCSevere Thunderstorm WarningMPX
16:20 UTC17:00 UTCSevere Thunderstorm WarningMPX
16:24 UTC17:00 UTCTornado 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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 12:32 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.

Minneapolis, MN (KMPX), 12:00Z

4.4 hours before the tornado, 111 km from the path. August 28, 2021.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2021-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1550 joules per kilogram, CIN -130, lifted condensation level 676 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, Minneapolis, MN at 12:00Z on 2021-08-28The 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 139 square meters per square second, 0 to 6 km bulk shear 29 knots.193958Sfc1 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
1550 J/kg
Mixed-layer CIN
-130 J/kg
Surface CAPE
216 J/kg
Mixed-layer LCL
676 m above ground
0-6 km bulk shear
29 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 00:00Z

7.6 hours after it, 111 km from the path. August 29, 2021.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1990 joules per kilogram, CIN -120, lifted condensation level 977 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, Minneapolis, MN at 00:00Z on 2021-08-29The 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 31 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
1990 J/kg
Mixed-layer CIN
-120 J/kg
Surface CAPE
2831 J/kg
Mixed-layer LCL
977 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.0
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

The surface observations

Paynesville (PEX), 26 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
14:35 UTC69.869.8110° 9 kt1012.2
14:55 UTC69.869.8120° 9 kt1012.2BR
15:15 UTC71.671.6130° 11 kt1012.2
15:35 UTC71.671.6130° 12 kt161011.2
15:55 UTC71.671.6140° 9 kt1010.8
16:15 UTC73.471.6250° 12 kt1014.6VCTS
16:35 UTC64.464.4330° 18 kt321015.6VCTSRA
16:55 UTC64.464.410° 13 kt271014.6-VCTSRA
17:15 UTC64.464.410° 5 kt161013.9
17:35 UTC66.264.450° 7 kt1014.2VCTS
17:55 UTC66.264.460° 9 kt141013.9VCTS
18:15 UTC69.866.270° 7 kt1013.2

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

The radar

The Minneapolis radar (KMPX), 113 km away, was scanning. The volume nearest the touchdown began at 16:25 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
15:54 UTCHAIL 1.254 Sw OsakisDouglas, MN
16:10 UTCTSTM WND DMGSauk CentreStearns, MNNUMEROUS TREES DOWN IN TOWN WITH URBAN FLOODING TIME ESTIMATED VIA RADAR.
16:32 UTCTSTM WND DMGAvonStearns, MNEMERGENCY MANAGEMENT REPORTS 10 TO 12 TREE LIMBS DOWN WITH TIME ESTIMATED BASED ON RADAR.
16:40 UTCTSTM WND DMGUpsalaMorrison, MNFEW TREES AND POWER LINES DOWN.
16:46 UTCHAIL 12 W UpsalaMorrison, MN
16:50 UTCHAIL 1.5SartellStearns, MNPING PONG BALL SIZED HAIL WITH ESTIMATED 58 MPH WINDS.
16:55 UTCHAIL 1.251 N Sauk RapidsBenton, MNHAIL DAMAGED HOME SIDING.
16:55 UTCHAIL 1.5Sauk RapidsBenton, MNTIME ESTIMATED BASED ON RADAR.
16:58 UTCHAIL 21 W RoyaltonMorrison, MN
17:00 UTCHAIL 1.755 Sw GilmanBenton, MNPICTURE FROM SOCIAL MEDIA WITH A HALF DOLLAR AND GOLF BALL SIZED HAIL STONE WITH TIME ESTIMATED BASED ON RADAR.
17:00 UTCHAIL 2.55 Ne Sauk RapidsBenton, MNHAIL WAS MEASURED. IT WAS ALSO WEIGHED THE NEXT DAY AT 2.64 OUNCES. MULTIPLE VEHICLES HAD WINDOWS BROKEN AND WERE DENTED. SIDING ON HOUSES WAS ALSO DENTED. WINDOWS WERE BROKEN IN HOUSES AND OUTBUILDINGS.

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 August 28, 2021

16 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 284:21 PM CDTUnratedTurner, SD0.540
August 284:22 PM CDTEF1Lincoln, SD2.3150$200,000
August 284:25 PM CDTUnratedLincoln, SD0.920
August 284:30 PM CDTUnratedLincoln, SD1.620
August 284:35 PM CDTUnratedLincoln, SD1.130
August 285:29 PM CDTUnratedMurray, MN1.240
August 285:40 PM CDTUnratedMurray, MN1.920
August 285:48 PM CDTUnratedMurray, MN0.620
August 285:53 PM CDTUnratedMurray, MN2.220
August 286:04 PM CDTUnratedCottonwood, MN3.520
August 286:29 PM CDTEF0Brown, MN3.320
August 286:29 PM CDTEF0Brown, MN4.325
August 286:47 PM CDTEF0Brown, MN0.925
August 286:52 PM CDTUnratedBrown, MN0.620
August 288:12 PM CDTEF0Waseca, MN0.725
August 288:14 PM CDTEF0Waseca, MN0.425

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.