Flash Flood and Hail in South Dakota, July 18, 2008

Name: Flash Flood and Hail in South Dakota, July 18, 2008
Start: 2008-07-18T03:00
End: 2008-07-18T06:20
Location: South Dakota

July 18, 2008 · NWS UNR · 4 events in 3 counties and zones

Severe thunderstorms produced quarter sized hail, heavy rain, and flash flooding across southwestern South Dakota during the early morning. One to two inches of rain in half an hour flooded roads and yards from Hot Springs to Cascade Falls.

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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 4

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.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Rapid City, SD wrote its last area forecast discussion before the first event at Jul 18, 1:44 AM MST, 1 hour 16 minutes earlier.

Area forecast discussion, Jul 18, 1:44 AM MST, 1 hour 16 minutes before

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Hazardous weather outlook, Jul 17, 6:47 AM MST, 20 hours 13 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
747 AM MDT THU JUL 17 2008

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-181000-
BENNETT-BUTTE-CENTRAL BLACK HILLS-CUSTER CO PLAINS-FALL RIVER-HAAKON-
HARDING-HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHEASTERN CROOK-
NORTHERN BLACK HILLS-NORTHERN CAMPBELL-NORTHERN FOOT HILLS-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY-
SHANNON-SOUTHERN BLACK HILLS-SOUTHERN CAMPBELL-SOUTHERN FOOT HILLS-
SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-
WESTERN CROOK-WESTON-WYOMING BLACK HILLS-ZIEBACH-
747 AM MDT (847 AM CDT) THU JUL 17 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND
NORTHEASTERN WYOMING.

.DAY ONE...TODAY AND TONIGHT

ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS THE AREA
TODAY. WIDESPREAD SEVERE WEATHER IS NO LONGER ANTICIPATED.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

AN ACTIVE SEVERE WEATHER PATTERN IS EXPECTED FRIDAY...WITH A SLIGHT
RISK OF SEVERE THUNDERSTORMS OVER NORTHEASTERN WYOMING AND WESTERN
SOUTH DAKOTA. LARGE HAIL AND AN ISOLATED TORNADO WILL BE THE MAIN
THREATS OVER NORTHEASTERN WYOMING...WHILE LARGE HAIL AND DAMAGING
WIND GUSTS WILL BE THE MAIN THREATS LATER FRIDAY EVENING AS THE
STORMS DEVELOP INTO WESTERN SOUTH DAKOTA.

SHOWERS AND THUNDERSTORMS ARE EXPECTED AGAIN ON SATURDAY...WITH THE
POSSIBILITY OF ADDITIONAL SEVERE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY.

In the hours before

Local storm report, Jul 18, 12:02 AM MST, 2 hours 58 minutes before

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The radar

The Rapid City radar (KUDX), 98 km away, was scanning. The volume nearest the first event began at 09:58 UTC.

Open the radar archive at this moment

Event by event

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

Hail, Custer

When: July 18, 3:00 AM MST
Where: Custer County, 9 mi SSW of Pringle
Measured: 0.75 in hail
Reported by: Public
Coordinates: 43.480, -103.669

Hail, Fall River

When: July 18, 3:30 AM MST
Where: Fall River County, 3 mi SW of Hot Springs
Measured: 1 in hail
Reported by: Emergency Manager
Coordinates: 43.399, -103.522

Hail was six to seven inches deep along Highway 71 from Cascade Falls to Hot Springs.

Flash Flood, Fall River

When: July 18, 3:40 AM MST to 6:00 AM MST
Where: Fall River County, 3.99 mi NNW of Hot Springs to 6.17 mi SSW of Hot Springs
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 43.480, -103.520

Water flowed over Joplin and South Sixth Streets in Hot Springs.

Hail, Bennett

When: July 18, 6:15 AM MST to 6:20 AM MST
Where: Bennett County, 10 mi N of Vetal
Measured: 1 in hail
Reported by: Public
Coordinates: 43.365, -101.380

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

Every storm in South Dakota in 2008 Every state in 2008 This day in weather history Warnings in South Dakota, July 2008

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: 116961, 116962, 130433, 116963.