South Dakota, 2018

Flash Flood and Hail in South Dakota, June 22, 2018

June 22, 2018 · NWS UNR · 17 events in 2 counties and zones

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.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
17

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS UNR wrote it up.

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.

The radar

The Rapid City radar (KUDX), 59 km away, was scanning. The volume nearest the first event began at 18:50 UTC.

Open the radar archive at this moment

Event by event

16 hail, 1 flash flood. Local standard time, as filed.

Hail, Pennington

When
June 22, 11:48 AM MST
Where
Pennington County, 4 mi N of Silver City
Measured
1.5 in hail
Reported by
Trained Spotter
Coordinates
44.138, -103.570

Hail, Pennington

When
June 22, 12:00 PM MST
Where
Pennington County, 2 mi NNE of Silver City
Measured
0.75 in hail
Reported by
Trained Spotter
Coordinates
44.107, -103.555

Hail, Pennington

When
June 22, 12:13 PM MST to 12:16 PM MST
Where
Pennington County, 1 mi NNW of Hisega
Measured
1 in hail
Reported by
Public
Coordinates
44.063, -103.408

Hail, Pennington

When
June 22, 12:15 PM MST
Where
Pennington County, 1 mi N of Hisega
Measured
1.75 in hail
Reported by
Trained Spotter
Coordinates
44.065, -103.400

Hail, Pennington

When
June 22, 12:16 PM MST
Where
Pennington County, 1 mi N of Hisega
Measured
1.75 in hail
Reported by
NWS Employee
Coordinates
44.065, -103.400

Hail, Pennington

When
June 22, 12:32 PM MST to 12:35 PM MST
Where
Pennington County, 2 mi SW of Rapid City
Measured
1 in hail
Reported by
NWS Employee
Coordinates
44.059, -103.258

Hail, Pennington

When
June 22, 12:34 PM MST
Where
Pennington County, 5 mi NE of Rockerville
Measured
1.25 in hail
Reported by
CoCoRaHS
Coordinates
44.011, -103.289

Hail, Pennington

When
June 22, 12:35 PM MST to 12:45 PM MST
Where
Pennington County, 1.06 mi ESE of Rapid City
Measured
0.75 in hail
Reported by
Official NWS Observations
Coordinates
44.073, -103.211

Hail, Pennington

When
June 22, 12:37 PM MST
Where
Pennington County, 5 mi SW of Rapid City
Measured
1.25 in hail
Reported by
Public
Coordinates
44.029, -103.301

Hail, Pennington

When
June 22, 12:40 PM MST
Where
Pennington County, 5 mi NE of Rockerville
Measured
1.5 in hail
Reported by
Public
Coordinates
44.011, -103.289

Hail, Pennington

When
June 22, 12:45 PM MST
Where
Pennington County, 5 mi ENE of Rockerville
Measured
1 in hail
Reported by
Public
Coordinates
43.988, -103.267

Flash Flood, Pennington

When
June 22, 12:45 PM MST to 3:20 PM MST
Where
Pennington County, 3.08 mi WSW of Rapid City to 3.91 mi SSE of Rapid City
Cause
Heavy Rain
Reported by
Trained Spotter
Coordinates
44.066, -103.289

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.

Hail, Pennington

When
June 22, 12:49 PM MST
Where
Pennington County, 4 mi S of Rapid City
Measured
1.25 in hail
Reported by
NWS Employee
Coordinates
44.022, -103.230

Hail, Pennington

When
June 22, 12:51 PM MST
Where
Pennington County, 2 mi NW of Rapid City
Measured
1.25 in hail
Reported by
Broadcast Media
Coordinates
44.100, -103.258

Hail, Pennington

When
June 22, 1:28 PM MST
Where
Pennington County, 7.04 mi ENE of Hayward
Measured
1.5 in hail
Reported by
Public
Coordinates
43.910, -103.200

Hail, Custer

When
June 22, 2:15 PM MST
Where
Custer County, 7 mi ESE of Hermosa
Measured
2 in hail
Reported by
Public
Coordinates
43.801, -103.060

Hail, Custer

When
June 22, 2:45 PM MST
Where
Custer County, 6.88 mi SW of Folsom
Measured
1 in hail
Reported by
Public
Coordinates
43.760, -102.980

What these are

Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Flash Flood
Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in South Dakota in 2018Every state in 2018This day in weather historyWarnings in South Dakota, June 2018

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 756731, 756732, 756733, 756734, 756736, 756737, 756738, 756740, 756741, 756743, 756744, 765169, 756746, 756748, 756749, 756750, 756751.