Hail, Bennett
- When
- May 9, 5:00 PM MST to 6:00 PM MST
- Where
- Bennett County, Martin
- Measured
- 1.75 in hail
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.170, -101.750
Tornadoes and Flash Flooding in South Dakota, May 9 to 26, 1999
23 hail, 10 tornado, 3 flash flood, 2 funnel cloud, as filed by the National Weather Service.
Where it happened
Every event with a place to put it; 5 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
The toll
- Deaths
- 0
- Injuries
- 1
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 38
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.
The radar
The Rapid City radar (KUDX), 137 km away, was scanning. The volume nearest the first event began at 00:00 UTC.
Event by event
23 hail, 10 tornado, 3 flash flood, 2 funnel cloud. Local standard time, as filed.
Tornado, Tripp
- When
- May 9, 5:32 PM MST
- Where
- Tripp County, 12 mi NW of Winner
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 1 yd
- Reported by
- TRAINED SPOTTER
- Coordinates
- 43.480, -100.030
Brief Touchdown. Tornado path and width estimated
Tornado, Tripp
- When
- May 9, 5:45 PM MST
- Where
- Tripp County, 6 mi NW of Hamill
- Rating
- F0
- Path length
- 1 mi
- Path width
- 10 yd
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.650, -99.770
A new barn had a portion of the roof torn off and thrown a quarter mile away, tree branches were snapped off and ground wires for power lines were snapped. A calving shed was also destroyed.
Tornado, Todd
- When
- May 9, 6:12 PM MST
- Where
- Todd County, 3 mi NE of Parmelee
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 1 yd
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.350, -100.970
Brief Touchdown. Tornado path and width estimated
Tornado, Mellette
- When
- May 9, 6:25 PM MST
- Where
- Mellette County, 2 mi N of White River
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 1 yd
- Reported by
- TRAINED SPOTTER
- Coordinates
- 43.600, -100.750
Brief Touchdown. Tornado path and width estimated
Tornado, Mellette
- When
- May 9, 6:25 PM MST
- Where
- Mellette County, 2 mi SW of White River
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 1 yd
- Reported by
- TRAINED SPOTTER
- Coordinates
- 43.550, -100.780
Brief Touchdown. Tornado path and width estimated
Tornado, Todd
- When
- May 9, 6:42 PM MST
- Where
- Todd County, 8 mi W of Mission
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 1 yd
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.300, -100.830
Brief Touchdown. Tornado path and width estimated
Hail, Tripp
- When
- May 9, 7:20 PM MST
- Where
- Tripp County, 4 mi E of Winner
- Measured
- 1.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.370, -99.780
Tornado, Todd
- When
- May 9, 7:26 PM MST
- Where
- Todd County, Mission
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 1 yd
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.300, -100.670
Brief Touchdown. Tornado path and width estimated
Tornado, Todd
- When
- May 9, 7:29 PM MST
- Where
- Todd County, 4 mi SW of Mission
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 1 yd
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.270, -100.720
Brief Touchdown. Tornado path and width estimated
Flash Flood, Mellette
- When
- May 9, 7:30 PM MST to May 10, 7:00 AM MST
- Where
- Mellette County, Countywide
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.581, -100.760 (the zone’s center; the record gives no point)
1 foot of water over Highway 63 after 2-4 inches of rain fell over the region. Numerous other county roads had water covering them also.
Hail, Todd
- When
- May 9, 7:50 PM MST
- Where
- Todd County, Mission
- Measured
- 1.75 in hail
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.300, -100.670
Flash Flood, Todd
- When
- May 9, 7:50 PM MST to May 10, 7:00 AM MST
- Where
- Todd County, Countywide
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.193, -100.718 (the zone’s center; the record gives no point)
Numerous roads in the county were flooded over after 2 to 4 inches of rain fell. Several creeks were overflowing thier banks.
Hail, Todd
- When
- May 9, 8:20 PM MST
- Where
- Todd County, St Francis
- Measured
- 1 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.130, -100.920
Several windows broken
Hail, Pennington
- When
- May 9, 8:30 PM MST
- Where
- Pennington County, Wall
- Measured
- 1 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 44.000, -102.230
Flash Flood, Tripp
- When
- May 9, 9:45 PM MST to May 10, 7:00 AM MST
- Where
- Tripp County, Countywide
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.346, -99.884 (the zone’s center; the record gives no point)
Numerous roads were underwater and several were washed out after thunderstorms dropped 2 to 4 inches of rain in over the area. White River at Oacoma reached 20.75 feet...flood stage is 15 feet.
Hail, Pennington
- When
- May 15, 3:40 PM MST
- Where
- Pennington County, Hill City to 8 mi of Hill City
- Measured
- 1 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 44.000, -103.420
Tornado, Lawrence
- When
- May 15, 3:43 PM MST to 3:50 PM MST
- Where
- Lawrence County, Spearfish to 10 mi NW of Spearfish
- Rating
- F0
- Path length
- 1 mi
- Path width
- 10 yd
- Reported by
- UNKNOWN
- Coordinates
- 44.600, -104.000
Brief Touchdown. Moved into Butte County.
Tornado, Butte
- When
- May 15, 3:50 PM MST to 3:53 PM MST
- Where
- Butte County, Belle Fourche to 12 mi SW of Belle Fourche
- Rating
- F0
- Path length
- 1 mi
- Path width
- 10 yd
- Reported by
- UNKNOWN
- Coordinates
- 44.550, -104.030
Stayed in open country...moved from Lawrence County into Butte County.
Hail, Pennington
- When
- May 15, 4:00 PM MST
- Where
- Pennington County, Hisega to 3 mi of Hisega
- Measured
- 0.75 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 44.080, -103.450
Hail, Meade
- When
- May 21, 1:30 PM MST to 1:40 PM MST
- Where
- Meade County, Tilford
- Measured
- 1.5 in hail
- Injuries
- 1 direct, 0 indirect
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 44.300, -103.420
1" to 1.5" hail...up to 6 inches deep on Interstate 90. A 5 car pile up left one person injured after several vehicles slid through the hail.
Hail, Meade
- When
- May 21, 3:05 PM MST
- Where
- Meade County, Ellsworth Afb
- Measured
- 1.75 in hail
- Reported by
- OTHER FEDERAL AGENCY
- Coordinates
- 44.150, -103.100
Funnel Cloud, Meade
- When
- May 21, 3:07 PM MST to 3:16 PM MST
- Where
- Meade County, Ellsworth Afb
- Reported by
- OTHER FEDERAL AGENCY
- Coordinates
- 44.567, -102.717 (the zone’s center; the record gives no point)
Hail, Harding
- When
- May 21, 3:09 PM MST
- Where
- Harding County, Redig
- Measured
- 0.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 45.270, -103.550
Hail, Pennington
- When
- May 21, 3:10 PM MST
- Where
- Pennington County, Boxelder
- Measured
- 1.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 44.120, -103.070
Funnel Cloud, Pennington
- When
- May 21, 3:10 PM MST to 3:35 PM MST
- Where
- Pennington County, Rapid City Arpt
- Reported by
- UNKNOWN
- Coordinates
- 44.004, -102.824 (the zone’s center; the record gives no point)
Several funnel clouds reported
Hail, Custer
- When
- May 21, 4:20 PM MST
- Where
- Custer County, 5 mi N of Dewey
- Measured
- 0.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.600, -104.030
Hail, Pennington
- When
- May 21, 4:45 PM MST
- Where
- Pennington County, Hill City to 8 mi of Hill City
- Measured
- 0.75 in hail
- Reported by
- OFFICIAL NWS OBS.
- Coordinates
- 43.830, -103.650
Hail, Custer
- When
- May 22, 5:21 AM MST
- Where
- Custer County, 1 mi N of Custer
- Measured
- 1 in hail
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.780, -103.600
Hail, Custer
- When
- May 22, 5:55 AM MST
- Where
- Custer County, Fairburn
- Measured
- 1 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.680, -103.220
Hail, Custer
- When
- May 22, 6:25 AM MST
- Where
- Custer County, 5 mi S of Custer
- Measured
- 0.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.700, -103.600
Hail, Oglala Lakota
- When
- May 22, 7:00 AM MST
- Where
- Oglala Lakota County, 2 mi N of Rockyford
- Measured
- 0.88 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.530, -102.500
Hail, Tripp
- When
- May 22, 9:20 AM MST
- Where
- Tripp County, Winner
- Measured
- 0.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.370, -99.870
Hail, Tripp
- When
- May 22, 9:30 AM MST to 9:40 AM MST
- Where
- Tripp County, 8 mi S of Winner
- Measured
- 1 in hail
- Reported by
- UNKNOWN
- Coordinates
- 43.250, -99.870
Hail, Todd
- When
- May 22, 10:00 AM MST
- Where
- Todd County, Parmelee
- Measured
- 1.25 in hail
- Reported by
- POST OFFICE
- Coordinates
- 43.320, -101.020
Hail, Lawrence
- When
- May 26, 1:47 PM MST to 1:59 PM MST
- Where
- Lawrence County, Lead
- Measured
- 1 in hail
- Reported by
- FIRE DEPT/RESCUE SQUAD
- Coordinates
- 44.350, -103.750
Hail, Meade
- When
- May 26, 2:42 PM MST to 2:50 PM MST
- Where
- Meade County, Sturgis
- Measured
- 0.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 44.420, -103.500
Hail, Ziebach
- When
- May 26, 4:30 PM MST
- Where
- Ziebach County, 5 mi SE of Glad Vly
- Measured
- 0.75 in hail
- Reported by
- UNKNOWN
- Coordinates
- 45.350, -101.680
What these are
- Hail
- Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
- Tornado
- A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
- 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.
- Funnel Cloud
- A rotating column of cloud extending from a thunderstorm that did not reach the ground.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornadoes and Flash Flood in Texas, May 9, 1999
- Hail and Damaging Winds in Oklahoma, May 9 to 10, 1999
- Damaging Winds in Iowa, May 9, 1999
- Hail and Damaging Winds in Tennessee, May 9 to 23, 1999
- Tornado and Hail in Oklahoma, May 9 to 10, 1999
- Damaging Wind in Texas, May 9, 1999
- Tornado and Flash Flood in Texas, May 9, 1999
- Hail in Florida, May 9, 1999
- Tornado and Hail in South Dakota, May 9, 1999
- Hail and Damaging Wind in Texas, May 9, 1999
- Flooding in South Dakota, May 9 to 31, 1999
- High Wind in Alaska, May 9 to 11, 1999
More
Every storm in South Dakota in 1999Every state in 1999This day in weather historyThe tornado archive for South Dakota, 1999Warnings in South Dakota, May 1999
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: 5698537, 5698538, 5698539, 5698540, 5698542, 5698543, 5698541, 5698544, 5698545, 5698546, 5698548, 5698547, 5698549, 5698550, 5698551, 5698552, 5698553, 5698671, 5698652, 5698554, 5698653, 5698655, 5698657, 5698654, 5698656, 5698658, 5698659, 5698660, 5698661, 5698662, 5698663, 5698664, 5698665, 5698666, 5698667, 5698668, 5698669, 5698670.