Two rounds of severe weather developed across central South Dakota during the afternoon and late evening hours. The first round of thunderstorms developed during the early afternoon hours of June 19th and quickly produced hail up to two inches in diameter. The thunderstorms proceeded to back build and train over the same areas for the next five hours finally exiting Hand county in the late afternoon.  As a result,  2 to 6 inches of rain had fallen causing flash flooding in northern Hyde and Hand counties. Flooded areas and creeks remained for the next few days.
The second round of thunderstorms developed late in the evening in western South Dakota transitioning into a widespread wind event as they moved quickly southeast into central South Dakota. During the event, winds from 60 to over 100 mph were measured with Jones, Lyman, and Buffalo counties being the hardest hit. The squall line entered Jones county around midnight and by 1230 am CDT, several semi trucks had been blown over, two machine sheds were destroyed, power poles and lines were snapped, numerous billboards and road signs were damaged, trailers were flipped over, a grain elevator bin's roof was blown off and side caved in, and many trees were downed. Much of the damage occurred in Okaton, Murdo, and Draper and along Interstate-90.
As the storms moved through Lyman County, they damaged several structures,   downed power lines and poles, flipped a pickup truck, along with causing expansive tree damage. In Buffalo county, the storms immediately impacted Fort Thompson, where campers were flipped, structures were damaged, and many trees were downed. Also, in Fort Thompson was the destruction of a trailer house which led to a fatality. The storm then impacted the rest of Buffalo county resulting in the destruction of several grain bins, a hay shed, along with taking the roof off of a hangar near Gann Valley before continuing east of the area.

Flood in HYDE, SOUTH DAKOTA
From 19-JUN-15 19:00:00 to 22-JUN-15 19:00:00 (CST-6)
Location: HOLABIRD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flooding of pasture and agricultural land, several creeks, along with a few roads continued after the earlier heavy rains subsided.

Flash Flood in HAND, SOUTH DAKOTA
From 19-JUN-15 13:15:00 to 19-JUN-15 18:15:00 (CST-6)
Location: POLO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Very heavy rains of 2 to 6 inches caused flooded creeks, fields, and roads.

Flash Flood in HYDE, SOUTH DAKOTA
From 19-JUN-15 14:00:00 to 19-JUN-15 19:00:00 (CST-6)
Location: HOLABIRD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Very heavy rains of 2 to 6 inches caused flash flooding of several creeks, roads, and fields.

Flood in HAND, SOUTH DAKOTA
From 19-JUN-15 18:15:00 to 22-JUN-15 18:15:00 (CST-6)
Location: POLO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flooding of pasture and agricultural land, several creeks, along with a few roads continued after the earlier heavy rains subsided.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:15:00 to 19-JUN-15 14:20:00 (CST-6)
Location: VAYLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 20-JUN-15 00:36:00 to 20-JUN-15 00:36:00 (CST-6)
Location: OACOMA
Magnitude: 70.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

Estimated eighty mph winds caused damage to the roof of a hotel along with snapping a street sign off. A freeway boom was also snapped.

Hail in SULLY, SOUTH DAKOTA
From 19-JUN-15 12:00:00 to 19-JUN-15 12:30:00 (CST-6)
Location: ONIDA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 20-JUN-15 00:05:00 to 20-JUN-15 00:05:00 (CST-6)
Location: LOWER BRULE
Magnitude: 78.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

Ninety mph winds flipped over a pickup truck, removed a large area of shingles on a roof, along with downing many large tree branches.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:15:00 to 19-JUN-15 14:25:00 (CST-6)
Location: VAYLAND
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:30:00 to 19-JUN-15 13:45:00 (CST-6)
Location: REE HGTS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:22:00 to 19-JUN-15 23:22:00 (CST-6)
Location: OKATON
Magnitude: 76.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in HYDE, SOUTH DAKOTA
From 19-JUN-15 12:05:00 to 19-JUN-15 12:05:00 (CST-6)
Location: HOLABIRD
Magnitude: 2.00 
Reported by: Amateur Radio

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:47:00 to 19-JUN-15 13:52:00 (CST-6)
Location: VAYLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:45:00 to 19-JUN-15 14:50:00 (CST-6)
Location: REE HGTS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:30:00 to 19-JUN-15 13:35:00 (CST-6)
Location: VAYLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:25:00 to 19-JUN-15 23:25:00 (CST-6)
Location: MURDO
Magnitude: 81.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:34:00 to 19-JUN-15 13:54:00 (CST-6)
Location: MILLER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 12:45:00 to 19-JUN-15 12:45:00 (CST-6)
Location: ST LAWRENCE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:30:00 to 19-JUN-15 14:45:00 (CST-6)
Location: VAYLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in STANLEY, SOUTH DAKOTA
From 20-JUN-15 16:13:00 to 20-JUN-15 16:13:00 (MST-7)
Location: SANSARC
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 20-JUN-15 00:25:00 to 20-JUN-15 00:25:00 (CST-6)
Location: OACOMA
Magnitude: 74.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:25:00 to 19-JUN-15 23:25:00 (CST-6)
Location: DRAPER
Magnitude: 70.00 EG
Crop damage: 0.00K
Reported by: Emergency Manager

Estimated eighty mph winds ripped off the machine shed doors and flipped over a trailer.

Thunderstorm Wind in HYDE, SOUTH DAKOTA
From 19-JUN-15 14:00:00 to 19-JUN-15 14:00:00 (CST-6)
Location: HOLABIRD
Magnitude: 52.00 EG
Crop damage: 0.00K
Reported by: Public

Sixty mph winds and golfball size hail put numerous holes in the siding of the house.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:40:00 to 19-JUN-15 14:10:00 (CST-6)
Location: ST LAWRENCE
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:27:00 to 19-JUN-15 13:27:00 (CST-6)
Location: MILLER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in HUGHES, SOUTH DAKOTA
From 19-JUN-15 13:26:00 to 19-JUN-15 13:46:00 (CST-6)
Location: HARROLD ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:20:00 to 19-JUN-15 23:20:00 (CST-6)
Location: MURDO
Magnitude: 78.00 EG
Crop damage: 0.00K
Reported by: Emergency Manager

Ninety mph winds flipped over a semi-trailer and small cargo trailer. The winds also downed power lines and damaged numerous billboards and road signs.

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:27:00 to 19-JUN-15 23:27:00 (CST-6)
Location: DRAPER
Magnitude: 61.00 EG
Crop damage: 0.00K
Reported by: Storm Chaser

Seventy mph winds caused some power flashes.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:20:00 to 19-JUN-15 14:25:00 (CST-6)
Location: VAYLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in BUFFALO, SOUTH DAKOTA
From 20-JUN-15 00:15:00 to 20-JUN-15 00:15:00 (CST-6)
Location: FT THOMPSON
Magnitude: 87.00 EG
Crop damage: 0.00K
Reported by: Law Enforcement

One-hundred mph winds or higher damaged or destroyed several homes, flipped many campers, and downed power lines and trees. Several trees fell onto homes.  One man died in a trailer home that was flipped.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:45:00 to 19-JUN-15 13:45:00 (CST-6)
Location: REE HGTS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:18:00 to 19-JUN-15 13:38:00 (CST-6)
Location: REE HGTS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:26:00 to 19-JUN-15 23:26:00 (CST-6)
Location: DRAPER
Magnitude: 78.00 EG
Crop damage: 0.00K
Reported by: Emergency Manager

Ninety mph winds caved in the side and blew the roof off a grain bin, knocked the doors off a machine shed, and flipped over a parked semi.

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 20-JUN-15 00:05:00 to 20-JUN-15 00:05:00 (CST-6)
Location: KENNEBEC
Magnitude: 70.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

Eighty mph winds caused damage to shingles on the roof.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:55:00 to 19-JUN-15 14:10:00 (CST-6)
Location: ST LAWRENCE
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 19-JUN-15 23:30:00 to 19-JUN-15 23:30:00 (CST-6)
Location: MC CLURE
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 13:45:00 to 19-JUN-15 13:55:00 (CST-6)
Location: MILLER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 19-JUN-15 23:50:00 to 19-JUN-15 23:50:00 (CST-6)
Location: KENNEBEC
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Many large tree branches were downed by seventy mph winds.

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:33:00 to 19-JUN-15 23:33:00 (CST-6)
Location: MURDO
Magnitude: 70.00 EG
Crop damage: 0.00K
Reported by: Storm Chaser

Estimated eighty mph winds resulted in a couple flipped trailers.

Thunderstorm Wind in STANLEY, SOUTH DAKOTA
From 19-JUN-15 22:10:00 to 19-JUN-15 22:10:00 (MST-7)
Location: HAYES
Magnitude: 70.00 EG
Crop damage: 0.00K
Reported by: COOP Observer

Eighty mph winds damaged several buildings and uprooted trees along with many branches broken off. Shingles were blown off several roofs along with some siding taken off the house. A utility trailer was also severely damaged with a propane tank tipped over.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:00:00 to 19-JUN-15 14:30:00 (CST-6)
Location: VAYLAND
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in HYDE, SOUTH DAKOTA
From 19-JUN-15 14:00:00 to 19-JUN-15 14:00:00 (CST-6)
Location: HOLABIRD
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:15:00 to 19-JUN-15 14:20:00 (CST-6)
Location: MILLER ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in BUFFALO, SOUTH DAKOTA
From 20-JUN-15 00:45:00 to 20-JUN-15 00:45:00 (CST-6)
Location: GANN VLY
Magnitude: 61.00 EG
Crop damage: 0.00K
Reported by: Public

Seventy mph winds took the tops off of a couple trees along with downing many large tree branches.

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 20-JUN-15 00:15:00 to 20-JUN-15 00:15:00 (CST-6)
Location: LOWER BRULE
Magnitude: 87.00 EG
Crop damage: 0.00K
Reported by: Newspaper

One-hundred mph winds or higher caused severe damage in Lower Brule to several buildings along with downing many trees.  The roof of the courthouse also sustained damage along with pieces of art destroyed, like tepees at the tribal hall. Light poles at the football field were also bent over. The red cross set up shelter for displaced people.

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:15:00 to 19-JUN-15 23:15:00 (CST-6)
Location: OKATON
Magnitude: 70.00 EG
Crop damage: 0.00K
Reported by: Law Enforcement

Eighty mph winds blew over a semi, destroyed several sheds, along with downing some power lines.

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:01:00 to 19-JUN-15 14:01:00 (CST-6)
Location: MILLER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:09:00 to 19-JUN-15 14:29:00 (CST-6)
Location: ST LAWRENCE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in HUGHES, SOUTH DAKOTA
From 19-JUN-15 23:41:00 to 19-JUN-15 23:41:00 (CST-6)
Location: PIERRE
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:30:00 to 19-JUN-15 14:40:00 (CST-6)
Location: VAYLAND
Magnitude: 1.50 
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in JONES, SOUTH DAKOTA
From 19-JUN-15 23:30:00 to 19-JUN-15 23:30:00 (CST-6)
Location: MURDO
Magnitude: 70.00 EG
Crop damage: 0.00K
Reported by: Law Enforcement

Eighty mph winds broke several trees off at the base with lots of tree branches downed.

Hail in HYDE, SOUTH DAKOTA
From 19-JUN-15 14:30:00 to 19-JUN-15 14:30:00 (CST-6)
Location: HOLABIRD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in BUFFALO, SOUTH DAKOTA
From 20-JUN-15 00:45:00 to 20-JUN-15 00:45:00 (CST-6)
Location: GANN VLY
Magnitude: 87.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

One-hundred mph winds destroyed some grain bins, hay shed, two buildings, and took the roof off of a hanger.

Thunderstorm Wind in HUGHES, SOUTH DAKOTA
From 19-JUN-15 23:40:00 to 19-JUN-15 23:40:00 (CST-6)
Location: BLUNT
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:30:00 to 19-JUN-15 14:45:00 (CST-6)
Location: VAYLAND
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Hail in HAND, SOUTH DAKOTA
From 19-JUN-15 14:25:00 to 19-JUN-15 14:35:00 (CST-6)
Location: VAYLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Thunderstorm Wind in LYMAN, SOUTH DAKOTA
From 19-JUN-15 23:31:00 to 19-JUN-15 23:31:00 (CST-6)
Location: PRESHO
Magnitude: 90.00 MG
Crop damage: 0.00K
Reported by: Mesonet