Flash Flood and Hail in South Dakota, August 8, 2002

Name: Flash Flood and Hail in South Dakota, August 8, 2002
Start: 2002-08-08T14:51
End: 2002-08-08T16:45
Location: South Dakota

August 8, 2002 · NWS UNR · 4 events in 1 county or zone

A powerful line of severe thunderstorms moved traversed Lawrence County entirely from west to east. Several reports of three-quarter inch diameter hail were received across the county.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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: $200,000
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.

A powerful line of severe thunderstorms moved traversed Lawrence County entirely from west to east. Several reports of three-quarter inch diameter hail were received across the county. The associated rainfall created flash flooding and mudslides in downtown Deadwood where a recent large forest fire had destroyed vegetation and severely burned the ground to within a few feet of structures in town. Mud and water two to three feet deep ran through downtown streets and businesses. Debris from the mudslides damaged several houses, vehicles, and the hospital.

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 8, 12:55 PM MST, 1 hour 56 minutes earlier.

Area forecast discussion, Aug 8, 12:55 PM MST, 1 hour 56 minutes before

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
155 PM MDT THU AUG 8 2002

...SEVERE THUNDERSTORM WATCH ENTIRE AREA EXCEPT CAMPBELL COUNTY
WYOMING THIS EVENING...
VIGOROUS PACIFIC SHORT WAVE MOVING INTO THE NORTHERN PLAINS THIS
AFTERNOON WILL CONTINUE TO PRODUCE INTENSE THUNDERSTORM ACTIVITY AS
IT MOVES OUT OF SOUTHERN MONTANA INTO NORTHEAST WYOMING AND WESTERN
SOUTH DAKOTA. FORECAST HODOGRAPHS INDICATE A PREFERENCE FOR LINEAR
ORGANIZATION...STRONG WINDS AND LARGE HAIL. THE WINDS ARE OF
PARTICULAR CONCERN FOR NWRN SD...N AND NE OF THE BLACK HILLS...SINCE
THE SHORT WAVE WILL CONTRIBUTE 50+ MPH WIND SPEEDS TO THE MID LEVELS
OF THE ATMOSPHERE ACROSS WRN SD BY MIDNIGHT.  SEVERE WEATHER
OPERATIONS IN PROGRESS AT UNR.

ONLY MINOR ADJUSTMENTS WERE MADE TO LATER PERIODS OF THE PACKAGE. A
SOMEWHAT UNSTABLE NW FLOW WILL KEEP THE WEATHER MODERATELY ACTIVE
THROUGH THE END OF THE WEEK...THEN LARGE SCALE SUBSIDENCE AND DRY
AIR WILL PROVIDE A RESPITE FROM MIDDAY SATURDAY THROUGH SUNDAY.
SUMMERTIME HEATING AND A WEAK MID LEVEL SHORT WAVE WILL PRODUCE SOME
WEATHER MON AND TUE...WITH FAIR SKIES DOMINATING WED AND THU.

.UNR...NONE.

CARPENTER

In the hours before

Local storm report, Aug 8, 10:31 AM MST, 4 hours 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1131 AM MDT THU AUG 08 2002

TIME(MDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0945 PM    3 NW FAIRPT               SD   65 MPH TSTM GUST
08/07/02   MEADE                          REPORTED BY PUBLIC.

1000 PM    1 S REVA                  SD    MPH TSTM GUST
08/07/02   HARDING                        EVENT DURATION 30
                                          MINUTES. REPORTED BY
                                          STORM SPOTTER.

1003 PM    ZEONA                     SD   70 MPH TSTM GUST
08/07/02   PERKINS                        REPORTED BY PUBLIC.

1030 PM    PRAIRIE CITY              SD   60 MPH TSTM GUST
08/07/02   PERKINS                        REPORTED BY STORM
                                          SPOTTER.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

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

Hail, Lawrence

When: August 8, 2:51 PM MST
Where: Lawrence County, 10 mi S of Spearfish
Measured: 0.75 in hail
Reported by: LAW ENFORCEMENT
Coordinates: 44.350, -103.850

Hail, Lawrence

When: August 8, 2:54 PM MST
Where: Lawrence County, Lead
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 44.350, -103.750

Flash Flood, Lawrence

When: August 8, 3:12 PM MST to 4:45 PM MST
Where: Lawrence County, Deadwood
Measured: 3
Property damage: $200,000
Reported by: EMERGENCY MANAGER
Coordinates: 44.359, -103.792 (the zone’s center; the record gives no point)

Hail, Lawrence

When: August 8, 3:15 PM MST
Where: Lawrence County, 5 mi S of Whitewood
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 44.400, -103.633

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 2002 Every state in 2002 This day in weather history Warnings in South Dakota, August 2002

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 2026-09-24. Each event’s entry at NCEI: 5310613, 5310614, 5310616, 5310615.