A frontal boundary provided focus for convective development across south central South Dakota during the very late afternoon and early evening as a strong impulse moved in the southwest flow aloft.  Initial discrete cells produced spotty hail and damaging wind, with MLCAPE values around 1500-2000 J/kg and 45-55 knots of deep-layer shear.  As cells spread eastward and developed into a line, the increase in low-level jet during the evening quickly increased the 0-3 km shear to 35-40 knots.  Three QLCS tornadoes occurred within the city limits of Sioux Falls.  In addition to the tornadoes, widespread wind damage to trees and spottier damage to residences were reported across much of the city.  A total of nine people were injured in the storms around Sioux Falls.  Repeated cells resulted in flash flooding by later evening and into the overnight hours.

Tornado in LINCOLN, SOUTH DAKOTA
From 10-SEP-19 22:24:00 to 10-SEP-19 22:25:00 (CST-6)
Location: TEA
Tornado F-scale: EF2
Property damage: 6.80M
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down around one quarter mile east of the intersection of Interstates 29 and 229, near the intersection of 69th Street and Tallgrass Avenue.  The tornado tracked east-northeast for a quarter mile before it struck a building under construction, causing extensive damage to concrete and metal framing, and tossed a construction truck 200 yards into a tree.  The tornado then damaged the Avera Heart and Behavioral Hospital Complex, where cars were displaced up to 100 feet and most windows were broken along with roof and facade damage to the hospital buildings. Eight people were injured by flying glass on the hospital complex.  The tornado lifted about 400 yards to the east of the hospital. Average path width was estimated at 40 yards. Property damage costs are rough estimates.

Tornado in LINCOLN, SOUTH DAKOTA
From 10-SEP-19 22:24:00 to 10-SEP-19 22:25:00 (CST-6)
Location: SIOUX FALLS
Tornado F-scale: EF2
Property damage: 1.20M
Crop damage: 0.00K
Reported by: NWS Storm Survey

Initial damage to a few power poles occurred as the tornado touched down at the intersection of 85th Street and Western Avenue in far southern portions of the Sioux Falls metro area.  The tornado tracked northeast for a quarter mile causing tree damage in a residential area before turning more northerly. The tornadic path was evident by scouring vegetation while moving through a wetland area, tossing a trampoline, and causing tree damage to adjacent residences.  As the tornado entered a residential area on the north end of the wetlands, more significant damage occurred to several single family residences, with loss of significant sections of roofs and walls, as well as numerous uprooted large trees.  At this point, the tornado turned northeast for the last quarter mile of its path, moving along La Quinta Street.  Two homes incurred more substantial damage with loss of exterior walls.  The tornado lifted before reaching Venita Avenue.  Average path width was estimated at 40 yards. Property damage costs are rough estimates.

Tornado in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:28:00 to 10-SEP-19 22:29:00 (CST-6)
Location: SOUTH SIOUX FALLS
Tornado F-scale: EF2
Property damage: 3.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

Shortly after touchdown just southeast of O'Gorman High School, the tornado struck a multi-story apartment building and removed a majority of the roof.  Numerous trees were uprooted in residential areas north of 41st Street as the tornado continued in a general southeast direction. The tornado crossed 41st Street into a more commercial district, causing significant structural damage to several businesses, including the removal of the roof from one strip mall and exterior walls from another building.  After another quarter mile of travel to the southeast, the tornado destroyed an apartment building garage.  The tornado lifted before reaching the corner of 49th Street and Western Avenue. Average path width was 50 yards. Property damage costs are rough estimates.

Thunderstorm Wind in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:31:00 to 10-SEP-19 22:33:00 (CST-6)
Location: SIOUX FALLS
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Public

Several trees down, with one onto a residence causing damage to roof and siding.

Thunderstorm Wind in MCCOOK, SOUTH DAKOTA
From 10-SEP-19 21:55:00 to 10-SEP-19 21:57:00 (CST-6)
Location: CANISTOTA
Magnitude: 52.00 MG
Reported by: Emergency Manager

Thunderstorm Wind in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:30:00 to 10-SEP-19 22:32:00 (CST-6)
Location: SIOUX FALLS
Magnitude: 70.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The facing and part of the roof of a business was torn off by thunderstorm winds. Surrounding areas had significant damage to trees, with several snapped or uprooted.

Thunderstorm Wind in LINCOLN, SOUTH DAKOTA
From 10-SEP-19 22:28:00 to 10-SEP-19 22:30:00 (CST-6)
Location: SIOUX FALLS
Magnitude: 61.00 EG
Property damage: 0.25K
Crop damage: 0.00K
Reported by: Public

Medium size ash tree broken off by thunderstorm winds.

Hail in CHARLES MIX, SOUTH DAKOTA
From 10-SEP-19 19:09:00 to 10-SEP-19 19:10:00 (CST-6)
Location: PLATTE
Magnitude: 1.00 
Reported by: Trained Spotter

Flash Flood in LAKE, SOUTH DAKOTA
From 11-SEP-19 04:00:00 to 11-SEP-19 05:30:00 (CST-6)
Location: MADISON
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rainfall produced flash flooding of Silver Creek on the southeast side of Madison.
Two to three feet of water made roads impassable.

Thunderstorm Wind in UNION, SOUTH DAKOTA
From 10-SEP-19 23:55:00 to 10-SEP-19 23:57:00 (CST-6)
Location: RICHLAND
Magnitude: 65.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Winds snapped a few large trees off a few feet above the ground.  Lots of tree limbs down, and numerous shingles removed from house.

Thunderstorm Wind in BRULE, SOUTH DAKOTA
From 10-SEP-19 17:35:00 to 10-SEP-19 17:36:00 (CST-6)
Location: PUKWANA
Magnitude: 52.00 EG
Reported by: Trained Spotter

Several 3-4 inch diameter limbs were snapped from trees.

Thunderstorm Wind in CHARLES MIX, SOUTH DAKOTA
From 10-SEP-19 18:26:00 to 10-SEP-19 18:28:00 (CST-6)
Location: ACADEMY
Magnitude: 62.00 MG
Reported by: Department of Highways

Thunderstorm Wind in BRULE, SOUTH DAKOTA
From 10-SEP-19 17:30:00 to 10-SEP-19 17:32:00 (CST-6)
Location: BIJOU HILLS
Magnitude: 52.00 EG
Reported by: Trained Spotter

Several tree limbs up to 3 inches in diameter snapped from trees.

Flash Flood in BROOKINGS, SOUTH DAKOTA
From 10-SEP-19 23:15:00 to 11-SEP-19 01:00:00 (CST-6)
Location: BROOKINGS
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several streets around town remained flooded, with the underpass on 6th Avenue pooled to several feet.

Flash Flood in DOUGLAS, SOUTH DAKOTA
From 10-SEP-19 23:00:00 to 11-SEP-19 02:00:00 (CST-6)
Location: ARMOUR
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

All roads leading into Delmont became impassable, with 6 inches or more flowing water over the roads. Numerous township roads in southeast Douglas County were also under water with several washed out culverts.

Tornado in BON HOMME, SOUTH DAKOTA
From 10-SEP-19 19:13:00 to 10-SEP-19 19:16:00 (CST-6)
Location: AVON
Tornado F-scale: EF0
Property damage: 6.00K
Reported by: Trained Spotter

A trained spotter observed the rapid spin up of a tornado to the west of his location 5 miles south of Avon, just north of 307th Street and west of 405th Avenue. The tornado tracked northeast, and moved into a farmstead as it crossed 306th Street. Roof panels were blown off a farm outbuilding, with doors on the building bowed inward. Several trees on the farmstead suffered damage to large branches.  The tornado continued to track northeast for around another half mile before lifting.  Average path width was 20 yards.

Thunderstorm Wind in DOUGLAS, SOUTH DAKOTA
From 10-SEP-19 19:20:00 to 10-SEP-19 19:22:00 (CST-6)
Location: JOUBERT
Magnitude: 61.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A barn was blown apart by thunderstorm winds north of Joubert.

Hail in BON HOMME, SOUTH DAKOTA
From 10-SEP-19 19:23:00 to 10-SEP-19 19:24:00 (CST-6)
Location: AVON
Magnitude: 1.00 
Reported by: Fire Department/Rescue

Thunderstorm Wind in AURORA, SOUTH DAKOTA
From 10-SEP-19 19:32:00 to 10-SEP-19 19:34:00 (CST-6)
Location: AURORA CENTER
Magnitude: 52.00 EG
Property damage: 0.25K
Reported by: Trained Spotter

Thunderstorm winds broke several limbs of 4 to 6 inches in diameter.

Flash Flood in BROOKINGS, SOUTH DAKOTA
From 10-SEP-19 22:51:00 to 11-SEP-19 00:30:00 (CST-6)
Location: BROOKINGS ARPT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Vehicles became stranded in flood waters after a period of intense rainfall.

Flash Flood in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:44:00 to 10-SEP-19 23:30:00 (CST-6)
Location: SIOUX FALLS
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Water ponded to a depth of 2 to 3 feet near 33rd Street and Minnesota Avenue.

Thunderstorm Wind in LINCOLN, SOUTH DAKOTA
From 10-SEP-19 22:30:00 to 10-SEP-19 22:32:00 (CST-6)
Location: SIOUX FALLS
Magnitude: 61.00 MG
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:31:00 to 10-SEP-19 22:33:00 (CST-6)
Location: SIOUX FALLS
Magnitude: 70.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Several large trees were uprooted or snapped.

Thunderstorm Wind in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:29:00 to 10-SEP-19 22:32:00 (CST-6)
Location: SOUTH SIOUX FALLS
Magnitude: 65.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Winds collapsed a residential structure and trapped three people. However, none were injured.

Thunderstorm Wind in AURORA, SOUTH DAKOTA
From 10-SEP-19 19:42:00 to 10-SEP-19 19:44:00 (CST-6)
Location: STICKNEY ARPT
Magnitude: 78.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Trained Spotter

An empty metal grain bin was blown apart by thunderstorm winds.

Thunderstorm Wind in AURORA, SOUTH DAKOTA
From 10-SEP-19 19:46:00 to 10-SEP-19 19:48:00 (CST-6)
Location: STICKNEY
Magnitude: 56.00 EG
Property damage: 0.25K
Reported by: Trained Spotter

Thunderstorms winds removed several tree limbs to 3 inches diameter.

Thunderstorm Wind in LINCOLN, SOUTH DAKOTA
From 10-SEP-19 22:23:00 to 10-SEP-19 22:24:00 (CST-6)
Location: SIOUX FALLS
Magnitude: 65.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Multiple shingles blown off a residence by thunderstorm winds, along with numerous tree branches of 1 to 2 inch diameter down.

Thunderstorm Wind in AURORA, SOUTH DAKOTA
From 10-SEP-19 19:48:00 to 10-SEP-19 19:50:00 (CST-6)
Location: STICKNEY
Magnitude: 61.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong winds blew pickup truck sideways and downed several larger limbs.

Hail in HUTCHINSON, SOUTH DAKOTA
From 10-SEP-19 20:00:00 to 10-SEP-19 20:02:00 (CST-6)
Location: TRIPP
Magnitude: 0.88 
Reported by: Trained Spotter

Thunderstorm Wind in TURNER, SOUTH DAKOTA
From 10-SEP-19 21:44:00 to 10-SEP-19 21:46:00 (CST-6)
Location: MARION
Magnitude: 70.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A farm outbuilding was blown over by thunderstorm winds.

Thunderstorm Wind in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:27:00 to 10-SEP-19 22:31:00 (CST-6)
Location: SOUTH SIOUX FALLS
Magnitude: 78.00 EG
Property damage: 750.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Significant damaging winds impacted areas for several blocks around 41st Street and Glendale Avenue.  Two apartment buildings had roofs torn off. One injury resulted from roof debris collapsing on a person in a single-family home.  The fabric portion of an inflatable sports dome was destroyed by the strong winds. Numerous large trees were uprooted or snapped, blocking roadways and damaging a few homes.

Thunderstorm Wind in TURNER, SOUTH DAKOTA
From 10-SEP-19 22:05:00 to 10-SEP-19 22:11:00 (CST-6)
Location: CHANCELLOR
Magnitude: 73.00 EG
Property damage: 75.00K
Reported by: NWS Storm Survey

A swath of wind damage began around 1 mile northwest of Chancellor where large tree limbs were broken.  One mile north of Chancellor, the strongest winds along the swath  caused extensive damage to a farmstead, destroying an outbuilding and a grain bin.  On the same property, an anchored playset and trees were damaged by straight line winds.  A few hundred yards east, metal roof panels were removed by the wind from a farm outbuilding.  There was no evidence along the damage path of a tornado due to a lack of convergence.  The damage path continued into Lincoln county.

Thunderstorm Wind in LINCOLN, SOUTH DAKOTA
From 10-SEP-19 22:11:00 to 10-SEP-19 22:17:00 (CST-6)
Location: LENNOX
Magnitude: 70.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

An extension of the path of wind damage from Turner County, winds from 70 to 80 mph continued to produce damage to trees and farm outbuildings until around 2 miles south of Tea.  Most of the damage to structures consisted of removed siding and roof panels.

Flash Flood in MCCOOK, SOUTH DAKOTA
From 10-SEP-19 22:15:00 to 11-SEP-19 01:00:00 (CST-6)
Location: CANISTOTA
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Water up to 2 feet in depth flooded many roads in Canistota.

Thunderstorm Wind in LINCOLN, SOUTH DAKOTA
From 10-SEP-19 22:17:00 to 10-SEP-19 22:19:00 (CST-6)
Location: TEA
Magnitude: 61.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Public

Debris from a metal barn was blown a long distance, and multiple spruce trees were snapped by thunderstorm winds.

Thunderstorm Wind in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:20:00 to 10-SEP-19 22:22:00 (CST-6)
Location: ELLIS
Magnitude: 61.00 EG
Reported by: Trained Spotter

Limbs up to 3 inches were broken from trees by strong thunderstorm winds.

Thunderstorm Wind in MINNEHAHA, SOUTH DAKOTA
From 10-SEP-19 22:27:00 to 10-SEP-19 22:30:00 (CST-6)
Location: SOUTH SIOUX FALLS
Magnitude: 70.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: NWS Employee

Significant tree damage occurred at Tomar, Yankton Trails, and Tuthill Parks.  Numerous large trees were snapped or uprooted.