A long-lived severe thunderstorm developed over the central Black Hills and moved slowly southeast onto the plains before weakening. The storm produced a large swath of large hail from the Silver City area to southeast of Hermosa. Heavy rainfall of two inches in a short time caused minor flooding across parts of Rapid City.

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 11:48:00 to 22-JUN-18 11:48:00 (MST-7)
Location: SILVER CITY
Magnitude: 1.50 
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:00:00 to 22-JUN-18 12:00:00 (MST-7)
Location: SILVER CITY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:13:00 to 22-JUN-18 12:16:00 (MST-7)
Location: HISEGA
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: Public

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:15:00 to 22-JUN-18 12:15:00 (MST-7)
Location: HISEGA
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:16:00 to 22-JUN-18 12:16:00 (MST-7)
Location: HISEGA
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: NWS Employee

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:32:00 to 22-JUN-18 12:35:00 (MST-7)
Location: RAPID CITY
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: NWS Employee

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:34:00 to 22-JUN-18 12:34:00 (MST-7)
Location: ROCKERVILLE
Magnitude: 1.25 
Crop damage: 0.00K
Reported by: CoCoRaHS

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:35:00 to 22-JUN-18 12:45:00 (MST-7)
Location: RAPID CITY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:37:00 to 22-JUN-18 12:37:00 (MST-7)
Location: RAPID CITY
Magnitude: 1.25 
Crop damage: 0.00K
Reported by: Public

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:40:00 to 22-JUN-18 12:40:00 (MST-7)
Location: ROCKERVILLE
Magnitude: 1.50 
Crop damage: 0.00K
Reported by: Public

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:45:00 to 22-JUN-18 12:45:00 (MST-7)
Location: ROCKERVILLE
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: Public

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:49:00 to 22-JUN-18 12:49:00 (MST-7)
Location: RAPID CITY
Magnitude: 1.25 
Crop damage: 0.00K
Reported by: NWS Employee

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:51:00 to 22-JUN-18 12:51:00 (MST-7)
Location: RAPID CITY
Magnitude: 1.25 
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 13:28:00 to 22-JUN-18 13:28:00 (MST-7)
Location: HAYWARD
Magnitude: 1.50 
Crop damage: 0.00K
Reported by: Public

Hail in CUSTER, SOUTH DAKOTA
From 22-JUN-18 14:15:00 to 22-JUN-18 14:15:00 (MST-7)
Location: HERMOSA
Magnitude: 2.00 
Crop damage: 0.00K
Reported by: Public

Hail in CUSTER, SOUTH DAKOTA
From 22-JUN-18 14:45:00 to 22-JUN-18 14:45:00 (MST-7)
Location: FOLSOM
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: Public

Flash Flood in PENNINGTON, SOUTH DAKOTA
From 22-JUN-18 12:45:00 to 22-JUN-18 15:20:00 (MST-7)
Location: RAPID CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Over an inch of rain fell in less than an hour, causing street flooding in parts of Rapid City. Several intersections and roads were covered with water; including west Main Street, Mountain View Road, and Fairmont Boulevard.