A mid-level disturbance moving from Wyoming into South Dakota initiated late evening convection in an environment with around 2000 J/kg MLCAPE and deep-layer shear of around 50 knots.  Storms expanded and rapidly evolved into a large-scale bow echo.

Tornado in KINGSBURY, SOUTH DAKOTA
From 28-AUG-20 00:26:00 to 28-AUG-20 00:27:00 (CST-6)
Location: DE SMET MUNI ARPT
Tornado F-scale: EFU
Crop damage: 33.00K
Reported by: NWS Storm Survey

A tornado formed just southwest of the intersection of 203rd Street and 428th Avenue.
During a brief touchdown and eastward travel, damage was limited to crops, marked by ground scour noted on high-resolution satellite data. The tornado lifted around a quarter mile east of 428th Avenue. Crop damage is an estimate from insured losses. Information provided by the United States Department of Agriculture.

Thunderstorm Wind in MCCOOK, SOUTH DAKOTA
From 28-AUG-20 01:13:00 to 28-AUG-20 01:16:00 (CST-6)
Location: MONTROSE
Magnitude: 50.00 MG
Reported by: Mesonet

South Dakota RWIS station SD547, three miles southeast of Montrose, measured a peak wind gust of 58 mph.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 27-AUG-20 23:54:00 to 27-AUG-20 23:56:00 (CST-6)
Location: WOLSEY
Magnitude: 53.00 MG
Reported by: Mesonet

South Dakota RWIS station SD582, 3 miles north northwest of Wolsey, measured a peak wind gust of 61 mph.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 27-AUG-20 23:55:00 to 27-AUG-20 23:58:00 (CST-6)
Location: (HON)HURON ARPT
Magnitude: 70.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A camper was flipped by strong thunderstorm winds. Property damage cost is a rough estimate.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 27-AUG-20 23:56:00 to 27-AUG-20 23:58:00 (CST-6)
Location: HURON
Magnitude: 61.00 EG
Property damage: 7.50K
Crop damage: 0.00K
Reported by: Social Media

A power pole was snapped off by thunderstorm winds. Property damage cost is a rough estimate.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 27-AUG-20 23:56:00 to 27-AUG-20 23:59:00 (CST-6)
Location: (HON)HURON ARPT
Magnitude: 70.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A portion of a garage roof was torn off.  A car and boat were rolled over near the house. Property damage costs are rough estimates.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 27-AUG-20 23:58:00 to 27-AUG-20 23:59:00 (CST-6)
Location: (HON)HURON ARPT
Magnitude: 70.00 MG
Reported by: Public

A personal weather station measured a wind gust of 80 mph.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 27-AUG-20 23:58:00 to 27-AUG-20 23:59:00 (CST-6)
Location: (HON)HURON ARPT
Magnitude: 73.00 MG
Reported by: ASOS

Automated weather station KHON near Huron, SD measured a peak wind gust of 84 mph.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 28-AUG-20 00:03:00 to 28-AUG-20 00:06:00 (CST-6)
Location: (HON)HURON ARPT
Magnitude: 61.00 EG
Reported by: Trained Spotter

Thunderstorm winds gusted several minutes to around 70 mph.

Thunderstorm Wind in BEADLE, SOUTH DAKOTA
From 28-AUG-20 00:14:00 to 28-AUG-20 00:17:00 (CST-6)
Location: CAVOUR
Magnitude: 65.00 MG
Reported by: Mesonet

South Dakota RWIS station SD515, three miles east of Cavour, measured a peak wind gust of 75 mph.

Tornado in KINGSBURY, SOUTH DAKOTA
From 28-AUG-20 00:27:00 to 28-AUG-20 00:28:00 (CST-6)
Location: DE SMET
Tornado F-scale: EF1
Property damage: 75.00K
Reported by: Law Enforcement

A tornado spun up west of 432nd Avenue and north of 211th Street.  As the tornado traveled generally eastward, ground scour was noted to crops.  The greatest damage occurred mid-track where a barn collapsed, with the debris blown downstream into another building. A few other outbuildings were also damaged. Large branches in tree breaks were snapped and the upper half of a concrete silo collapsed. The tornado dissipated one quarter mile east of 432nd Avenue around 3 miles south-southwest of De Smet. Property damage costs are rough estimates.

Thunderstorm Wind in KINGSBURY, SOUTH DAKOTA
From 28-AUG-20 00:32:00 to 28-AUG-20 00:35:00 (CST-6)
Location: DE SMET MUNI ARPT
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Winds tipped over a trailer and ripped siding off a tin shed.  Several trees had broken limbs. Property damage costs are rough estimates.

Thunderstorm Wind in KINGSBURY, SOUTH DAKOTA
From 28-AUG-20 00:37:00 to 28-AUG-20 00:39:00 (CST-6)
Location: LAKE PRESTON ARPT
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Strong winds collapsed part of a concrete silo and severely damaged the roof and walls of an old barn and another farm outbuilding.  Several large trees were snapped by thunderstorm wind. Property damage costs are rough estimates.

Thunderstorm Wind in KINGSBURY, SOUTH DAKOTA
From 28-AUG-20 00:52:00 to 28-AUG-20 00:55:00 (CST-6)
Location: BADGER
Magnitude: 56.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Tree branches from 2 to 6 inches in diameter were removed by thunderstorm winds. Property damage costs are rough estimates.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 28-AUG-20 00:55:00 to 28-AUG-20 00:58:00 (CST-6)
Location: AHNBERG
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Social Media

Several trees were downed on a property, and one large tree crushed a swing set. Property damage costs are rough estimates.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 28-AUG-20 01:03:00 to 28-AUG-20 01:06:00 (CST-6)
Location: BRUCE
Magnitude: 56.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Scattered tree damage was reported in Bruce. Property damage costs are rough estimates.

Thunderstorm Wind in MOODY, SOUTH DAKOTA
From 28-AUG-20 01:17:00 to 28-AUG-20 01:19:00 (CST-6)
Location: SIOUX FALLS JCT
Magnitude: 50.00 MG
Crop damage: 3.00K
Reported by: Mesonet

South Dakota RWIS station SD577, 10 miles south southwest of Aurora, measured a peak wind gust of 58 mph. Crop damage is an estimate from insured losses. Information provided by the United States Department of Agriculture.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 28-AUG-20 01:21:00 to 28-AUG-20 01:23:00 (CST-6)
Location: WHITE
Magnitude: 51.00 MG
Reported by: Mesonet

South Dakota State University mesonet station at Oak Lake measured a peak wind gust of 59 mph.