Thunderstorms produced large hail at numerous locations in southeast South Dakota, south of Interstate 90, on August 18th, mostly during the late morning and afternoon. There were also a few reports of damaging thunderstorm winds.

Hail in BON HOMME, SOUTH DAKOTA
From 18-AUG-11 01:12:00 to 18-AUG-11 01:12:00 (CST-6)
Location: SCOTLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in CHARLES MIX, SOUTH DAKOTA
From 18-AUG-11 10:40:00 to 18-AUG-11 10:40:00 (CST-6)
Location: MARTY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Thunderstorm winds caused tree damage, including several large branches blown down.

Hail in BON HOMME, SOUTH DAKOTA
From 18-AUG-11 11:30:00 to 18-AUG-11 11:35:00 (CST-6)
Location: PERKINS
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Trained Spotter

Large hail dented a few vehicles. The hail was accompanied by winds gusting to about 45 mph.

Hail in BON HOMME, SOUTH DAKOTA
From 18-AUG-11 13:12:00 to 18-AUG-11 13:12:00 (CST-6)
Location: SCOTLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in YANKTON, SOUTH DAKOTA
From 18-AUG-11 13:30:00 to 18-AUG-11 13:30:00 (CST-6)
Location: LESTERVILLE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Golf ball size hail caused an unknown amount of property and crop damage. The property damage consisted mainly of several dented vehicles.

Hail in YANKTON, SOUTH DAKOTA
From 18-AUG-11 14:43:00 to 18-AUG-11 14:43:00 (CST-6)
Location: GAYVILLE
Magnitude: 1.00 
Property damage: 0.00K
Reported by: Storm Chaser

Large hail covered the ground and caused crop damage in the area. The amount of crop damage was not known.

Hail in BON HOMME, SOUTH DAKOTA
From 18-AUG-11 15:45:00 to 18-AUG-11 15:45:00 (CST-6)
Location: SCOTLAND
Magnitude: 1.50 
Property damage: 10.00K
Reported by: Trained Spotter

Large hail caused damage to bean and corn crops. The amount of crop damage was not known. The hail also dented a few vehicles.

Hail in CLAY, SOUTH DAKOTA
From 18-AUG-11 16:06:00 to 18-AUG-11 16:11:00 (CST-6)
Location: DALESBURG
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in YANKTON, SOUTH DAKOTA
From 18-AUG-11 16:25:00 to 18-AUG-11 16:25:00 (CST-6)
Location: YANKTON
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Hail in YANKTON, SOUTH DAKOTA
From 18-AUG-11 16:29:00 to 18-AUG-11 16:29:00 (CST-6)
Location: YANKTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in YANKTON, SOUTH DAKOTA
From 18-AUG-11 16:29:00 to 18-AUG-11 16:29:00 (CST-6)
Location: MISSION HILL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in YANKTON, SOUTH DAKOTA
From 18-AUG-11 16:48:00 to 18-AUG-11 16:48:00 (CST-6)
Location: GAYVILLE
Magnitude: 1.75 
Property damage: 10.00K
Reported by: Trained Spotter

Large hail dented vehicles and caused crop damage. The amount of crop damage was not known from this hail or from earlier hail in the same afternoon.

Hail in BON HOMME, SOUTH DAKOTA
From 18-AUG-11 18:00:00 to 18-AUG-11 18:00:00 (CST-6)
Location: AVON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in BON HOMME, SOUTH DAKOTA
From 18-AUG-11 18:06:00 to 18-AUG-11 18:06:00 (CST-6)
Location: PERKINS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in BON HOMME, SOUTH DAKOTA
From 18-AUG-11 18:15:00 to 18-AUG-11 18:15:00 (CST-6)
Location: PERKINS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in YANKTON, SOUTH DAKOTA
From 18-AUG-11 14:09:00 to 18-AUG-11 14:20:00 (CST-6)
Location: YANKTON
Magnitude: 66.00 MG
Property damage: 500.00K
Reported by: AWOS

Thunderstorm winds caused widespread tree damage, including numerous trees blown down. Some homes were damaged by falling trees or tree debris. The winds drove hail that was up to golf ball size, and with the hail contributed to crop damage in the area.

Hail in YANKTON, SOUTH DAKOTA
From 18-AUG-11 14:09:00 to 18-AUG-11 14:20:00 (CST-6)
Location: (YKN)CHAN GURNEY ARP
Magnitude: 1.75 
Property damage: 2.00M
Reported by: Department of Highways

Large hail up to golf ball size, driven by strong to damaging winds, caused widespread property and crop damage in and near Yankton. Numerous windows were broken, both in structures and in vehicles, roofs and siding were damaged in several homes and businesses, and trees were stripped. Corn and other crops in the area were heavily damaged, with crops totally stripped in some areas. The amount of crop damage could not yet be determined.