Several supercell thunderstorms brought very heavy rains of 4 to 7 inches, hail up to golfball size, winds to over 100 mph, along with a tornado to parts of north central South Dakota. Dewey county was the most affected by the storms.

Thunderstorm Wind in POTTER, SOUTH DAKOTA
From 16-JUN-10 22:45:00 to 16-JUN-10 22:45:00 (CST-6)
Location: GETTYSBURG
Magnitude: 52.00 EG
Reported by: Public

Sixty mph winds were estimated by the public.

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:20:00 to 16-JUN-10 19:30:00 (MST-7)
Location: LANTRY
Magnitude: 123.00 MG
Reported by: Mesonet

Three weather stations near Lantry observed winds from 101 to 142 mph.  One station recorded a 101 mph wind before it was destroyed. The other two stations recorded 131 mph and 142 mph winds.  The winds destroyed an airplane hanger and badly damaged another one.  Several semi-trailers were also tipped over and damaged by the very high winds.

Tornado in DEWEY, SOUTH DAKOTA
From 16-JUN-10 18:35:00 to 16-JUN-10 18:38:00 (MST-7)
Location: LANTRY
Tornado F-scale: EF2
Reported by: NWS Storm Survey

A tornado touched down briefly on a farm six miles northwest of Eagle Butte. Two homes suffered severe structural damage with several pole barns destroyed. Also several pieces of agricultural equipment were damaged or destroyed. A horse was severely injured and had to be put down. Wind speeds were estimated between 120 and 125 mph.

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:15:00 to 16-JUN-10 19:15:00 (MST-7)
Location: BEAR CREEK
Magnitude: 87.00 EG
Reported by: Emergency Manager

One hundred mph winds overturned and severely damaged a mobile home north of Lantry. The occupants in the mobile home received only minor injuries.

Thunderstorm Wind in WALWORTH, SOUTH DAKOTA
From 16-JUN-10 23:05:00 to 16-JUN-10 23:05:00 (CST-6)
Location: LOWRY
Magnitude: 70.00 EG
Reported by: Public

Eighty mph winds shifted a wood grainery off of it's foundation about eight inches.

Thunderstorm Wind in WALWORTH, SOUTH DAKOTA
From 16-JUN-10 23:15:00 to 16-JUN-10 23:15:00 (CST-6)
Location: LOWRY
Magnitude: 61.00 EG
Reported by: Insurance Company

Seventy mph winds took out a door and the back wall of an old barn.

Thunderstorm Wind in WALWORTH, SOUTH DAKOTA
From 16-JUN-10 23:15:00 to 16-JUN-10 23:15:00 (CST-6)
Location: LOWRY
Magnitude: 70.00 EG
Reported by: Trained Spotter

A couple large cottonwood trees were uprooted by eighty mph winds.

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 18:30:00 to 16-JUN-10 18:30:00 (MST-7)
Location: BEAR CREEK
Magnitude: 56.00 MG
Reported by: Mesonet

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:00:00 to 16-JUN-10 19:00:00 (MST-7)
Location: LANTRY
Magnitude: 52.00 EG
Reported by: Public

Sixty mph winds were estimated by the public.

Flash Flood in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:50:00 to 17-JUN-10 03:00:00 (MST-7)
Location: BEAR CREEK
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Very heavy rains of 4 to 7 inches caused flash flooding in several areas along Highway 212 from west of Lantry to Eagle Butte. Several homes and businesses along with most roads in Eagle Butte were flooded with quite a bit of damage received.

Funnel Cloud in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:40:00 to 16-JUN-10 19:40:00 (MST-7)
Location: BEAR CREEK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:30:00 to 16-JUN-10 19:30:00 (MST-7)
Location: BEAR CREEK
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Trained Spotter

Golfball size hail broke the windshield on a vehicle.

Hail in WALWORTH, SOUTH DAKOTA
From 16-JUN-10 23:10:00 to 16-JUN-10 23:10:00 (CST-6)
Location: SELBY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:05:00 to 16-JUN-10 19:05:00 (MST-7)
Location: BEAR CREEK
Magnitude: 93.00 MG
Reported by: Mesonet

Winds gusting to near 110 mph were measured near Bear Creek.

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:40:00 to 16-JUN-10 19:40:00 (MST-7)
Location: LANTRY
Magnitude: 70.00 EG
Reported by: Trained Spotter

Eighty mph winds severely damaged several trees near the area.

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:40:00 to 16-JUN-10 19:40:00 (MST-7)
Location: EAGLE BUTTE
Magnitude: 87.00 EG
Reported by: Public

One hundred mph winds flattened a pole barn, toppled and severely damaged several grain bins, and shattered the glass out of a tractor.

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 19:45:00 to 16-JUN-10 19:45:00 (MST-7)
Location: EAGLE BUTTE
Magnitude: 87.00 EG
Reported by: Public

One hundred mph winds flattened a pole barn and blew two horse trailers into a tractor.  The horse trailers and the tractor were damaged.

Thunderstorm Wind in DEWEY, SOUTH DAKOTA
From 16-JUN-10 20:45:00 to 16-JUN-10 20:45:00 (MST-7)
Location: PARADE
Magnitude: 56.00 EG
Reported by: Public

Sixty-five mph winds were estimated southeast of Parade.