A secondary wave of severe thunderstorms developed over southwest Minnesota by the late afternoon of Saturday, August 28th. This area of storms formed a bow-echo that moved from Springfield, east-northeast toward New Ulm, Mankato, and Le Center. The most intense part of the bow-echo occurred at the onset that moved across Brown and Watonwan counties. Several tornadoes were documented. Thousands of acres of corn was flattened due to sustained intense winds. As the storm progressed northeast, the bow-echo segment became disorganized south of the Twin Cities metro area. Another wave of storms that originated over southwest Minnesota during the evening, caused strong winds in Brown County but no damage was reported.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:45:00 to 28-AUG-21 17:46:00 (CST-6)
Location: ESSIG
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:33:00 to 28-AUG-21 17:34:00 (CST-6)
Location: GODAHL
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:40:00 to 28-AUG-21 17:40:00 (CST-6)
Location: HANSKA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Several trees and large branches were broken. A few hundred acres of corn were flattened at County Road 20 and 130th Avenue. An adjacent short damage path was determined to have been associated with a misocyclone, based on the damage pattern, Sentinel satellite imagery, and radar. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:39:00 to 28-AUG-21 17:40:00 (CST-6)
Location: COBDEN
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A small and narrow misocyclone on the leading edge of a storm traveled across corn and bean fields only. Drone video was utilized and an on-site survey was performed. The path was also identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Tornado in BROWN, MINNESOTA
From 28-AUG-21 17:29:00 to 28-AUG-21 17:35:00 (CST-6)
Location: COBDEN
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Satellite imagery revealed a damage path through crops, and a damage survey noted large branches down. Time based on radar. QLCS tornado.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:44:00 to 28-AUG-21 17:45:00 (CST-6)
Location: SLEEPY EYE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:44:00 to 28-AUG-21 17:45:00 (CST-6)
Location: SLEEPY EYE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:45:00 to 28-AUG-21 17:47:00 (CST-6)
Location: ESSIG
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in WATONWAN, MINNESOTA
From 28-AUG-21 17:28:00 to 28-AUG-21 17:28:00 (CST-6)
Location: SVEADAHL
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

There were several trees blown down around the Sveadahl community.

Thunderstorm Wind in WATONWAN, MINNESOTA
From 28-AUG-21 17:32:00 to 28-AUG-21 17:34:00 (CST-6)
Location: ST JAMES
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A few trees were blown down in St. James.

Thunderstorm Wind in NICOLLET, MINNESOTA
From 28-AUG-21 18:07:00 to 28-AUG-21 18:07:00 (CST-6)
Location: OSHAWA
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter had a hand held wind sensor that measured 52 knots.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:20:00 to 28-AUG-21 17:20:00 (CST-6)
Location: COMFREY
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large tree was uprooted in Comfrey.

Tornado in BROWN, MINNESOTA
From 28-AUG-21 17:29:00 to 28-AUG-21 17:37:00 (CST-6)
Location: LEAVENWORTH
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Satellite imagery revealed a damage path through crops, and a damage survey noted large branches down in two locations. Time based on radar. QLCS tornado.

Tornado in BROWN, MINNESOTA
From 28-AUG-21 17:47:00 to 28-AUG-21 17:49:00 (CST-6)
Location: ESSIG
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Track based on satellite imagery and damage survey. Time based on radar. Tornado knocked down large branches in a small grove at the end of its path.

Tornado in BROWN, MINNESOTA
From 28-AUG-21 17:52:00 to 28-AUG-21 17:53:00 (CST-6)
Location: ESSIG
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Satellite image showed tornado path through corn that matched up with circulation on radar. Damage survey could not locate any downed branches or any other damage indicator.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:22:00 to 28-AUG-21 17:25:00 (CST-6)
Location: COMFREY
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A large tree was snapped off the top, with several other smaller trees blown down north of Comfrey.

Thunderstorm Wind in NICOLLET, MINNESOTA
From 28-AUG-21 17:45:00 to 28-AUG-21 17:45:00 (CST-6)
Location: COURTLAND
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A large tree was broken off several feet above its base in Courtland.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:35:00 to 28-AUG-21 17:50:00 (CST-6)
Location: LEAVENWORTH
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Thousands of acres of corn were flattened by intense west and northwest winds across a broad area in western and southern Brown County. Some trees were blown down or damaged as well, including at a park on the northeast side of Altermatt Lake.

Tornado in WASECA, MINNESOTA
From 28-AUG-21 19:14:00 to 28-AUG-21 19:15:00 (CST-6)
Location: NEW RICHLAND
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A damage survey noted several trees were damaged at a farmstead, with large branches down. Satellite imagery showed more details to the tornado path. A time-stamped photo from a storm chaser showed a visible funnel in the area where the tornado damage occurred, and the photo was consistent with the tornado being in the flanking line.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:31:00 to 28-AUG-21 17:32:00 (CST-6)
Location: SPRINGFIELD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:32:00 to 28-AUG-21 17:33:00 (CST-6)
Location: SPRINGFIELD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in LE SUEUR, MINNESOTA
From 28-AUG-21 18:20:00 to 28-AUG-21 18:22:00 (CST-6)
Location: LE SUEUR
Magnitude: 48.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

There were a number of large tree limbs blown down near Le Sueur. One that was 12 inches in diameter.

Funnel Cloud in WATONWAN, MINNESOTA
From 28-AUG-21 17:45:00 to 28-AUG-21 17:45:00 (CST-6)
Location: MADELIA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter observed a funnel cloud north of Madelia.

Tornado in WASECA, MINNESOTA
From 28-AUG-21 19:12:00 to 28-AUG-21 19:13:00 (CST-6)
Location: NEW RICHLAND
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Radar shows this tornado occurred with a flanking line, just south of precipitation echoes. A damage survey revealed mostly corn damage, but some large branches were knocked down at a farmstead and some plywood was blown into a field. The damage survey revealed it was tornadic.  Satellite imagery revealed more detail about the exact path through fields. Storm chaser video definitely shows the tornado and correct time, which was consistent with this being a tornado from a flanking line.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:40:00 to 28-AUG-21 17:40:00 (CST-6)
Location: SLEEPY EYE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

There were several trees and many large branches blown down in the south half of Sleepy Eye, just east if Highway 4. A few trees and branches fell on houses and vehicles. A damage survey by the NWS was inconclusive, as the damage had been cleaned up quickly. The south to north path did seem to broaden out somewhat.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:31:00 to 28-AUG-21 17:32:00 (CST-6)
Location: SPRINGFIELD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:29:00 to 28-AUG-21 17:30:00 (CST-6)
Location: LEAVENWORTH
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.

Thunderstorm Wind in BROWN, MINNESOTA
From 28-AUG-21 17:37:00 to 28-AUG-21 17:38:00 (CST-6)
Location: COBDEN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow path of crop damage, possibly related to a misovortex within a broader wind field, was identified using Sentinel satellite imagery. It was not possible to correlate the crop damage with any radar circulation.