Flash Flood and Hail in South Dakota, July 15, 2016

Name: Flash Flood and Hail in South Dakota, July 15, 2016
Start: 2016-07-15T13:30
End: 2016-07-15T17:30
Location: South Dakota

July 15, 2016 · NWS UNR · 7 events in 1 county or zone

A severe thunderstorm developed southwest of Rapid City, producing hail to the size of quarters and two to five inches of rain in less than three hours. Runoff from the rain caused flash flooding in Wild Irishman Gulch, Red Rock Canyon, Cleghorn Canyon, and Nameless Cave Canyon.

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: 7

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 15, 10:32 AM MST, 2 hours 58 minutes earlier.

Area forecast discussion, Jul 15, 10:32 AM MST, 2 hours 58 minutes before

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Hazardous weather outlook, Jul 15, 5:23 AM MST, 8 hours 7 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
623 AM MDT FRI JUL 15 2016

WYZ054-055-058-161230-
NORTHERN CAMPBELL-SOUTHERN CAMPBELL-WESTON-
623 AM MDT FRI JUL 15 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
WYOMING.

.DAY ONE...TODAY AND TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS MAINLY LATER THIS AFTERNOON
AND TONIGHT. SOME OF THE STORMS COULD BE STRONG WITH A MARGINAL
RISK FOR LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORMS ARE POSSIBLE SATURDAY AND SUNDAY...ESPECIALLY IN THE
AFTERNOON AND EVENING HOURS. SOME OF THE STORMS COULD BE STRONG
WITH A MARGINAL RISK FOR LARGE HAIL AND DAMAGING
WINDS...ESPECIALLY SATURDAY AFTERNOON.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

&&

STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES...
OR CHECK OUR WEB SITE AT WEATHER.GOV/RAPIDCITY

SDZ012-024>031-041-042-044-047-072>074-WYZ056-057-071-161230-
BUTTE-NORTHERN BLACK HILLS-NORTHERN FOOT HILLS-RAPID CITY-
SOUTHERN FOOT HILLS-CENTRAL BLACK HILLS-SOUTHERN BLACK HILLS-
CUSTER CO PLAINS-PENNINGTON CO PLAINS-FALL RIVER-OGLALA LAKOTA-
BENNETT-TODD-STURGIS/PIEDMONT FOOT HILLS-SOUTHERN MEADE CO PLAINS-
HERMOSA FOOT HILLS-WESTERN CROOK-WYOMING BLACK HILLS-
NORTHEASTERN CROOK-
623 AM MDT FRI JUL 15 2016 /723 AM CDT FRI JUL 15 2016/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
SOUTH DAKOTA...THE BLACK HILLS OF SOUTH DAKOTA...WESTERN SOUTH
DAKOTA...NORTHEAST WYOMING...AND THE BLACK HILLS OF WYOMING.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE POSSIBLE TODAY AND TONIGHT. SOME OF THE STORMS
COULD BE STRONG LATER THIS AFTERNOON AND TONIGHT WITH A MARGINAL
RISK FOR LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

EXPECT SOME THUNDERSTORMS SATURDAY AND SUNDAY. THERE IS A SLIGHT
RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON AND EVENING WITH
THE THREAT OF VERY LARGE HAIL...GREATER THAN TWO INCHES IN
DIAMETER...DAMAGING WINDS...AND ISOLATED TORNADOES. SOME OF THE
STORMS SUNDAY AFTERNOON AND EVENING COULD BE STRONG WITH A
MARGINAL RISK FOR LARGE HAIL AND DAMAGING WINDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

&&

STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES...
OR CHECK OUR WEB SITE AT WEATHER.GOV/RAPIDCITY

SDZ001-002-013-014-032-043-046-049-161230-
HARDING-PERKINS-NORTHERN MEADE CO PLAINS-ZIEBACH-HAAKON-JACKSON-
MELLETTE-TRIPP-
623 AM MDT FRI JUL 15 2016 /723 AM CDT FRI JUL 15 2016/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
SOUTH DAKOTA...AND WESTERN SOUTH DAKOTA.

.DAY ONE...TODAY AND TONIGHT

EXPECT A FEW THUNDERSTORMS TODAY AND TONIGHT...ESPECIALLY EARLY
THIS MORNING AND LATE TONIGHT. ORGANIZED SEVERE THUNDERSTORMS ARE
NOT EXPECTED.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

EXPECT SOME THUNDERSTORMS SATURDAY AND SUNDAY. THERE IS A SLIGHT
RISK OF SEVERE THUNDERSTORMS LATER SATURDAY AFTERNOON AND EVENING
WITH THE THREAT OF VERY LARGE HAIL...GREATER THAN TWO INCHES IN
DIAMETER...DAMAGING WINDS...AND ISOLATED TORNADOES. ORGANIZED
SEVERE THUNDERSTORMS ARE NOT EXPECTED SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

&&

STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES...
OR CHECK OUR WEB SITE AT WEATHER.GOV/RAPIDCITY

The radar

The Rapid City radar (KUDX), 46 km away, was scanning. The volume nearest the first event began at 20:28 UTC.

Open the radar archive at this moment

Event by event

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

Heavy Rain, Pennington

When: July 15, 1:30 PM MST to 3:05 PM MST
Where: Pennington County, 1 mi N of Hisega
Reported by: Amateur Radio
Coordinates: 44.065, -103.400

Rainfall total of 4.11 inches in about one and a half hours.

Heavy Rain, Pennington

When: July 15, 2:20 PM MST to 5:30 PM MST
Where: Pennington County, 0.66 mi WNW of Johnson Siding
Reported by: River/Stream Gage
Coordinates: 44.082, -103.443

The river gauge on Rapid Creek above Johnson Siding recorded 3.08 inches of rain in three hours.

Heavy Rain, Pennington

When: July 15, 2:30 PM MST to 5:00 PM MST
Where: Pennington County, 4.69 mi NE of Rockerville
Reported by: CoCoRaHS
Coordinates: 44.013, -103.301

Rainfall total of 3.49 inches fell in two and a half hours.

Hail, Pennington

When: July 15, 4:12 PM MST
Where: Pennington County, 3.72 mi NE of Rockerville
Measured: 1 in hail
Reported by: NWS Employee
Coordinates: 44.000, -103.310

Flash Flood, Pennington

When: July 15, 4:15 PM MST to 4:45 PM MST
Where: Pennington County, 1.64 mi ENE of Johnson Siding to 3.71 mi SW of Hisega
Cause: Heavy Rain
Reported by: Public
Coordinates: 44.090, -103.400

Runoff from heavy rain overwhelmed culverts and flowed over Red Rock Road, Nameless Cave Road, and Cleghorn Canyon Road. Several feet of water were reported flowing through Wild Irishman Gulch.

Hail, Pennington

When: July 15, 4:20 PM MST
Where: Pennington County, 5.66 mi SSW of Rapid City
Measured: 1 in hail
Reported by: Public
Coordinates: 44.002, -103.255

Hail, Pennington

When: July 15, 4:28 PM MST
Where: Pennington County, 8 mi S of Rapid City
Measured: 0.75 in hail
Reported by: NWS Employee
Coordinates: 43.964, -103.220

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
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 2016 Every state in 2016 This day in weather history Warnings in South Dakota, July 2016

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 2026-09-30. Each event’s entry at NCEI: 645188, 645194, 645193, 644347, 645187, 644348, 644350.