An instability axis stretching from northeast Montana through western North Dakota was the focus for evening thunderstorms as a mid level short wave pushed across the western Dakotas.
Storms initially remained sub-severe early in the evening, producing non-severe hail across Williams and Billings Counties.  A small-scale supercell thunderstorm increased in strength as it approached the city of Dickinson in Stark County, and produced several microbursts from the west side of Dickinson, southeast across south central Stark County and into eastern Hettinger County. Winds up to 90 miles per hour were estimated from a storm survey conducted by the National Weather Service.

Thunderstorm Wind in STARK, NORTH DAKOTA
From 06-AUG-13 19:25:00 to 06-AUG-13 19:30:00 (MST-7)
Location: (DIK)DICKINSON MUNI
Magnitude: 76.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Dickinson Airport manager indicated there was no damage at or around the airport.

Thunderstorm Wind in STARK, NORTH DAKOTA
From 06-AUG-13 19:36:00 to 06-AUG-13 19:41:00 (MST-7)
Location: LEFOR
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

This was a public report of very strong winds.  Intermittent power outages were also reported.

Thunderstorm Wind in HETTINGER, NORTH DAKOTA
From 06-AUG-13 20:28:00 to 06-AUG-13 20:35:00 (MST-7)
Location: MOTT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Pea size hail accompanied the strong winds.

Funnel Cloud in STARK, NORTH DAKOTA
From 06-AUG-13 19:13:00 to 06-AUG-13 19:17:00 (MST-7)
Location: DICKINSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

There were several reports of a funnel cloud on the west side of Dickinson.  A broadcast media web cam reportedly depicted a brief funnel for thirty seconds around three thousand feet off the ground. Other reports of the funnel came from the public and local law enforcement.

Thunderstorm Wind in STARK, NORTH DAKOTA
From 06-AUG-13 19:15:00 to 06-AUG-13 19:27:00 (MST-7)
Location: DICKINSON
Magnitude: 78.00 EG
Property damage: 850.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A National Weather Service Storm Survey was done on the west side of Dickinson where wind damage occurred. The very high winds blew the roof off a storage unit and blew doors in. The debris from this building was blown to the southeast, and resulted in additional damage to several other buildings and vehicles. The damage surveyed was consistent with straight line winds and not a tornado.  The damage surveyed indicated peak wind speeds of approximately 90 miles per hour.

Hail in WILLIAMS, NORTH DAKOTA
From 06-AUG-13 18:29:00 to 06-AUG-13 18:34:00 (CST-6)
Location: WILLISTON
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WILLIAMS, NORTH DAKOTA
From 06-AUG-13 18:29:00 to 06-AUG-13 18:34:00 (CST-6)
Location: (ISN)SLOULIN FLD WIL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Hail in BILLINGS, NORTH DAKOTA
From 06-AUG-13 18:33:00 to 06-AUG-13 18:38:00 (MST-7)
Location: FAIRFIELD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winds up to 45 miles per hour were also reported.

Hail in STARK, NORTH DAKOTA
From 06-AUG-13 19:06:00 to 06-AUG-13 19:12:00 (MST-7)
Location: DICKINSON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter