8.1.00 Spearfish, SD

On this night a line of thunderstorms developed over extreme southeastern Montana and moved southeast into South Dakota. Radar looked impressive as the storms moved into the northern Black Hills. A bow echo developed and the storms produced severe straight line winds from Spearfish to Rapid City. I watched the storms approach from Skyline Drive in Rapid City. The lightning illuminated shelf cloud was well defined, and I watched as the strong winds approached from the northwest. Lights in the Blackhawk area grew dim as a line of dust raced toward me. Minutes later, strong winds, hail and heavy rain hammered Rapid City. Little did I know that the 60 mph winds Rapid City was experiencing were nothing compared to what Spearfish endured.

The next day, I conducted an aerial survey of the damage with a NWS forecaster. Spearfish airport received heavy damage and the ASOS recorded a wind of 97 mph before power was lost. Over 12 planes were severely damaged along with numerous hangars. Two mobile homes were flipped off their foundation and destroyed. A man rode it out for awhile in one of the homes before being thrown clear. Tree damage was also extensive on some of the hills peaks.

	Spearfish airport. View is looking north. The hangars in the northern portion of the picture were blown southeast. One of the planes in the lower picture came from a row of hangars completely destroyed.

	Spearfish airport. 1st picture is looking east and 2nd picture is looking south-southwest. Damage path flows parallel to the runway at about 120 degrees magnetic.

	Awning blown over in Spearfish.
	Bails of hay that were stripped show evidence of strong straight line winds. View is looking east and path of stripped hay is southeast.
	These two mobile homes were flipped completely over. One person survived uninjured while riding through the destruction.
	Damage highway signs were numerous.
	Damage highway signs were numerous.
	Storage buildings with roofs completely gone.
	Super 8 with extensive roof damage.
	Tree blown down on one of the peaks east of Spearfish airport.
	Hole in factory wall.
	This garage was completely destroyed. There was also wind damage to the roof of the main home. This was the only damage we could find that had a path other than southeast. In this case, the damage path extended northeast on the leeward side of a ridgeline. This home was located near Whitewood, SD.