Thunderstorms produced large hail, damaging winds, and flash flooding in southeast South Dakota during the late afternoon and early evening of July 17th. The storms developed initially over a long distance from Gregory to the Brookings area. The storms quickly weakened except for the storms near the eastern border of the state, which remained severe for several hours and eventually moved east.

Hail in DAVISON, SOUTH DAKOTA
From 17-JUL-10 17:32:00 to 17-JUL-10 17:32:00 (CST-6)
Location: MITCHELL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in GREGORY, SOUTH DAKOTA
From 17-JUL-10 16:58:00 to 17-JUL-10 16:58:00 (CST-6)
Location: GREGORY ARPT
Magnitude: 2.00 
Reported by: Public

Large hail caused an unknown amount of damage to crops and vehicles.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 17:48:00 to 17-JUL-10 17:48:00 (CST-6)
Location: BRUCE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds caused tree damage, including 5 inch diameter branches blown down.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 17:55:00 to 17-JUL-10 17:55:00 (CST-6)
Location: BRUCE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Thunderstorm winds caused tree damage, including several large trees blown down, and other large trees split.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 18:12:00 to 17-JUL-10 18:12:00 (CST-6)
Location: WHITE
Magnitude: 61.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm winds destroyed a pole barn, heavily damaged a metal storage building, and caused tree damage.

Hail in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 18:43:00 to 17-JUL-10 18:43:00 (CST-6)
Location: BROOKINGS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 18:51:00 to 17-JUL-10 18:51:00 (CST-6)
Location: VOLGA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 18:51:00 to 17-JUL-10 18:51:00 (CST-6)
Location: BROOKINGS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 18:51:00 to 17-JUL-10 18:51:00 (CST-6)
Location: VOLGA
Magnitude: 2.00 
Crop damage: 0.00K
Reported by: Trained Spotter

Large hail caused generally minor damage to vehicles. Most of the hail was penny size or smaller, with a few stones up to 2 inches in diameter. Several of the larger stones were flat with visible rings.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 17:50:00 to 17-JUL-10 17:50:00 (CST-6)
Location: BRUCE
Magnitude: 61.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Newspaper

Thunderstorm winds caused widespread tree damage at Oakwood Lakes State Park. A few vehicles were damaged by tree debris, a boat landing was damaged, and a camper was overturned, resulting in minor injuries.

Hail in LAKE, SOUTH DAKOTA
From 17-JUL-10 19:00:00 to 17-JUL-10 19:00:00 (CST-6)
Location: NUNDA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 19:05:00 to 17-JUL-10 19:05:00 (CST-6)
Location: AURORA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds caused tree damage, including 10 inch diameter limbs blown down. The winds were accompanied by heavy rain.

Flash Flood in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 19:10:00 to 17-JUL-10 22:30:00 (CST-6)
Location: BROOKINGS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain caused flash flooding of numerous streets and basements in Brookings. Knee deep water in several streets was slow to recede.

Hail in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 19:20:00 to 17-JUL-10 19:20:00 (CST-6)
Location: BROOKINGS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail was accompanied by heavy rain.

Hail in MOODY, SOUTH DAKOTA
From 17-JUL-10 19:37:00 to 17-JUL-10 19:37:00 (CST-6)
Location: FLANDREAU
Magnitude: 1.50 
Property damage: 25.00K
Reported by: Public

Large hail was accompanied by wind gusts up to 40 mph. The hail caused damage to several vehicles, and also caused an unknown amount of crop damage.

Thunderstorm Wind in BROOKINGS, SOUTH DAKOTA
From 17-JUL-10 18:55:00 to 17-JUL-10 18:55:00 (CST-6)
Location: BROOKINGS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds caused tree damage, including up to 5 inch diameter branches blown down.