Hail and Damaging Winds in South Dakota, August 12, 2023

Name: Hail and Damaging Winds in South Dakota, August 12, 2023
Start: 2023-08-12T12:55
End: 2023-08-12T15:52
Location: South Dakota

August 12, 2023 · NWS UNR · 10 events in 3 counties and zones

A supercell thunderstorm developed over the northern Black Hills and tracked southeast into the eastern Foothills and then onto the adjacent plains before weakening as it moved across the west central South Dakota plains. The storm produced hail larger than golf ball size and eventually strong wind gusts on the plains.

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: 10

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 Aug 12, 12:45 PM MST, 10 minutes earlier.

Area forecast discussion, Aug 12, 12:45 PM MST, 10 minutes before

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Hazardous weather outlook, Aug 12, 1:24 AM MST, 11 hours 31 minutes before

Hazardous Weather Outlook
National Weather Service Rapid City SD
224 AM MDT Sat Aug 12 2023

SDZ002-013-014-026>032-041>044-046-047-049-072>074-131300-
Perkins-Northern Meade Co Plains-Ziebach-Rapid City-
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Pennington Co Plains-Haakon-Fall River-
Oglala Lakota-Jackson-Bennett-Mellette-Todd-Tripp-
Sturgis/Piedmont Foot Hills-Southern Meade Co Plains-
Hermosa Foot Hills-
224 AM MDT Sat Aug 12 2023 /324 AM CDT Sat Aug 12 2023/

This Hazardous Weather Outlook is for portions of western South
Dakota and northeastern Wyoming.

.DAY ONE...Today and Tonight

There is a marginal risk (level 1 of 5) of severe thunderstorms
today, meaning that isolated severe storms are possible. Primary
hazards include large hail and damaging winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

There is a chance of thunderstorms on Sunday. Severe thunderstorms
are not expected at this time. On Sunday, northwest winds will
gust up to 45 mph on the plains of western South Dakota.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

SDZ001-012-024-025-WYZ054>058-071-131300-
Harding-Butte-Northern Black Hills-Northern Foot Hills-
Northern Campbell-Southern Campbell-Western Crook-
Wyoming Black Hills-Weston-Northeastern Crook-
224 AM MDT Sat Aug 12 2023

This Hazardous Weather Outlook is for portions of western South
Dakota and northeastern Wyoming.

.DAY ONE...Today and Tonight

There is a chance of thunderstorms this afternoon into tonight.
Severe thunderstorms are not expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

There is a chance of thunderstorms on Sunday. Severe thunderstorms
are not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

In the hours before

Special weather statement, Aug 12, 12:43 PM MST, 12 minutes before

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The radar

The Rapid City radar (KUDX), 66 km away, was scanning. The volume nearest the first event began at 19:54 UTC.

Open the radar archive at this moment

Event by event

8 hail, 2 thunderstorm wind. Local standard time, as filed.

Hail, Lawrence

When: August 12, 12:55 PM MST
Where: Lawrence County, 7.46 mi W of Nemo
Measured: 1.25 in hail
Reported by: Trained Spotter
Coordinates: 44.200, -103.650

Hail, Pennington

When: August 12, 1:20 PM MST
Where: Pennington County, 2 mi NE of Silver City
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 44.100, -103.541

Hail, Pennington

When: August 12, 1:20 PM MST
Where: Pennington County, 2 mi NNE of Silver City
Measured: 1.5 in hail
Reported by: Public
Coordinates: 44.107, -103.555

Hail, Pennington

When: August 12, 2:00 PM MST
Where: Pennington County, Sheridan Lake
Measured: 2 in hail
Reported by: Public
Coordinates: 43.980, -103.480

Hail, Pennington

When: August 12, 2:10 PM MST
Where: Pennington County, Rockerville
Measured: 1.75 in hail
Reported by: Fire Department/Rescue
Coordinates: 43.960, -103.360

Thunderstorm Wind, Custer

When: August 12, 2:45 PM MST to 3:05 PM MST
Where: Custer County, Hermosa
Measured: 61 kt (70 mph) estimated gust
Reported by: Fire Department/Rescue
Coordinates: 43.840, -103.190

A power line was knocked down and a mobile home was tipped over by strong winds.

Hail, Custer

When: August 12, 3:05 PM MST
Where: Custer County, Hermosa
Measured: 2 in hail
Reported by: Public
Coordinates: 43.840, -103.190

Hail, Custer

When: August 12, 3:05 PM MST
Where: Custer County, 1 mi W of Hermosa
Measured: 1.75 in hail
Reported by: Public
Coordinates: 43.840, -103.210

Hail, Custer

When: August 12, 3:50 PM MST
Where: Custer County, 7.07 mi SSW of Folsom
Measured: 1.5 in hail
Reported by: Trained Spotter
Coordinates: 43.720, -102.900

Thunderstorm Wind, Custer

When: August 12, 3:52 PM MST
Where: Custer County, 6.53 mi SSW of Folsom
Measured: 53 kt (61 mph) measured gust
Reported by: Mesonet
Coordinates: 43.730, -102.910

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

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

The same day elsewhere

Every storm in South Dakota in 2023 Every state in 2023 This day in weather history Warnings in South Dakota, August 2023

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: 1119200, 1119203, 1119206, 1119208, 1119210, 1119219, 1119220, 1119224, 1119227, 1119228.