Severe thunderstorms developed and remained stationary over the northeastern slopes of the Black Hills, producing very large hail and heavy rain. The most extensive damage was in the Piedmont area, where the hail broke windows and damaged roofs. Interstate 90 was lined with numerous vehicles that stopped after being damaged by the hail.

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 14:25:00 to 17-AUG-07 14:25:00 (MST-7)
Location: TILFORD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 15:15:00 to 17-AUG-07 15:15:00 (MST-7)
Location: TILFORD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 15:25:00 to 17-AUG-07 15:25:00 (MST-7)
Location: TILFORD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in LAWRENCE, SOUTH DAKOTA
From 17-AUG-07 15:00:00 to 17-AUG-07 15:00:00 (MST-7)
Location: GALENA
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in LAWRENCE, SOUTH DAKOTA
From 17-AUG-07 15:00:00 to 17-AUG-07 15:00:00 (MST-7)
Location: GALENA
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in LAWRENCE, SOUTH DAKOTA
From 17-AUG-07 15:00:00 to 17-AUG-07 15:00:00 (MST-7)
Location: GALENA
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 15:40:00 to 17-AUG-07 15:55:00 (MST-7)
Location: PIEDMONT
Magnitude: 2.75 
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Hail ranged from just under an inch to almost three inches in diameter.

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 15:48:00 to 17-AUG-07 15:48:00 (MST-7)
Location: PIEDMONT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 15:55:00 to 17-AUG-07 15:55:00 (MST-7)
Location: TILFORD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 15:55:00 to 17-AUG-07 15:55:00 (MST-7)
Location: TILFORD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 16:25:00 to 17-AUG-07 16:25:00 (MST-7)
Location: PIEDMONT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 16:27:00 to 17-AUG-07 16:27:00 (MST-7)
Location: PIEDMONT
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 17-AUG-07 16:50:00 to 17-AUG-07 16:50:00 (MST-7)
Location: RAPID CITY
Magnitude: 2.75 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 17:30:00 to 17-AUG-07 17:30:00 (MST-7)
Location: BLACK HAWK
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 17-AUG-07 17:30:00 to 17-AUG-07 17:30:00 (MST-7)
Location: HISEGA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in PENNINGTON, SOUTH DAKOTA
From 17-AUG-07 17:30:00 to 17-AUG-07 17:30:00 (MST-7)
Location: HISEGA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in MEADE, SOUTH DAKOTA
From 17-AUG-07 14:30:00 to 17-AUG-07 20:00:00 (MST-7)
Location: TILFORD
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Law Enforcement

An estimated four to six inches of rain and hail to the size of baseballs caused localized flooding between Piedmont and Tilford, especially near poor drainage areas and at a barricade along a frontage road. The water washed over several roads and was several inches deep over Interstate 90, forcing law enforcement officials to close it for a couple of hours.

Hail in MEADE, SOUTH DAKOTA
From 17-AUG-07 17:00:00 to 17-AUG-07 17:00:00 (MST-7)
Location: PIEDMONT
Magnitude: 2.00 
Property damage: 1.00M
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in LAWRENCE, SOUTH DAKOTA
From 17-AUG-07 14:35:00 to 17-AUG-07 14:35:00 (MST-7)
Location: GALENA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public