A supercell thunderstorm developed near Piedmont and moved slowly southeastward across the Rapid City area and the eastern foothills of the Black Hills. The storm produced very large hail, which caused significant property damage from Johnson Siding and Hisega to Rapid City. The storm also spawned a very brief tornado over prairie land east of Hermosa. Runoff from the slow moving thunderstorm caused street flooding in Rapid City and Rapid Creek to quickly rise into the greenway through town.

Hail in MEADE, SOUTH DAKOTA
From 30-AUG-13 12:00:00 to 30-AUG-13 12:00:00 (MST-7)
Location: PIEDMONT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 12:40:00 to 30-AUG-13 12:50:00 (MST-7)
Location: JOHNSON SIDING
Magnitude: 4.25 
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Public

Softball size hail caused extensive property damage to buildings and vehicles along Norris Peak Road.

Hail in MEADE, SOUTH DAKOTA
From 30-AUG-13 12:42:00 to 30-AUG-13 12:42:00 (MST-7)
Location: BLACK HAWK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Hail in MEADE, SOUTH DAKOTA
From 30-AUG-13 12:30:00 to 30-AUG-13 13:00:00 (MST-7)
Location: BLACK HAWK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 12:45:00 to 30-AUG-13 13:00:00 (MST-7)
Location: RAPID CITY
Magnitude: 2.75 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Hail damaged a vehicle and shingles on the house.

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 13:00:00 to 30-AUG-13 13:10:00 (MST-7)
Location: RAPID CITY
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 13:01:00 to 30-AUG-13 13:05:00 (MST-7)
Location: RAPID CITY
Magnitude: 1.75 
Property damage: 10.00M
Crop damage: 0.00K
Reported by: NWS Employee

Hail caused extensive damage to homes and vehicles on the west side of Rapid City.

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 12:55:00 to 30-AUG-13 13:40:00 (MST-7)
Location: RAPID CITY
Magnitude: 1.75 
Property damage: 10.00M
Crop damage: 0.00K
Reported by: Official NWS Observations

Hail to the size of golf balls fell at the Rapid City National Weather Service office and across much of east Rapid City.

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 13:30:00 to 30-AUG-13 13:40:00 (MST-7)
Location: RAPID CITY
Magnitude: 2.25 
Property damage: 12.00M
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 13:33:00 to 30-AUG-13 13:33:00 (MST-7)
Location: RAPID CITY
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 13:45:00 to 30-AUG-13 13:45:00 (MST-7)
Location: (RAP)RAPID CITY ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 14:10:00 to 30-AUG-13 14:10:00 (MST-7)
Location: CAPUTA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in CUSTER, SOUTH DAKOTA
From 30-AUG-13 14:44:00 to 30-AUG-13 14:44:00 (MST-7)
Location: FOLSOM
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

A small tornado briefly touched down in a pasture east of Hermosa.

Thunderstorm Wind in CUSTER, SOUTH DAKOTA
From 30-AUG-13 14:35:00 to 30-AUG-13 14:35:00 (MST-7)
Location: HERMOSA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Wind gusts were estimated at 60 mph.

Hail in CUSTER, SOUTH DAKOTA
From 30-AUG-13 14:35:00 to 30-AUG-13 14:35:00 (MST-7)
Location: FOLSOM
Magnitude: 1.75 
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Public

Hail in CUSTER, SOUTH DAKOTA
From 30-AUG-13 14:45:00 to 30-AUG-13 15:05:00 (MST-7)
Location: FOLSOM
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 13:30:00 to 30-AUG-13 15:00:00 (MST-7)
Location: RAPID CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Runoff from over an inch of rain in less than an hour caused street flooding in Rapid City with water levels reaching the top of the curbs on streets from West Boulevard to Mountain View Road. Several intersections were flooded, including West Main Street at Soo San Drive and West Boulevard at Saint Joseph Street.

Hail in PENNINGTON, SOUTH DAKOTA
From 30-AUG-13 13:00:00 to 30-AUG-13 13:05:00 (MST-7)
Location: HISEGA
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter