7.10.00 Piedmont, SD

A severe storm developed in the Deadwood, SD area and slowly moved southeast towards Rapid City. I left the house at 315 pm and headed north on I-90. During the drive, I could see well organized updraft towers. I arrived at Tilford Road at 355 pm and searched for an elevated location to view the storm. I could not find a good location as the updraft base was still over the Black Hills and the I-90 corridor sits in a valley. I, therefore, drove south on I-90 to Elk Creek Road. Enroute a radar indicated tornado warning was issued. I was still having difficulty seeing the base of the updraft so I drove south again to Stagebarn Canyon Drive which is just south of Piedmont, SD. There I was able to get to an elevated position and had a good view of the updraft base by 428 pm.

A well defined wall cloud was visible with the storm, but no sign of a visible tornado. I watched the storm move southeast for about 30 minutes before I again needed to reposition to the south. The forward flank precipitation downdraft was approaching from the north. So at 5 pm, I drove towards Skyline drive and hit the peak of Rapid City's "rush hour" traffic. It never fails, when you are trying to stay in front of a storm, either traffic or construction always slows you down.

I reached Skyline Drive around 530 pm. The storm was now in the Blackhawk, SD area with reports of strong winds and hail. For the next 20 minutes, the storm seemed to weaken and also changed direction from southeast to south. This kept the storm west of Rapid City. I returned home around 6 pm, and shortly after arriving, the storm reenergized one last time before completely dissipating. During this increase in intensity, the storm also began moving to the north. It put down some impressive lightning bolts before finally dying.

	307 pm View looking northwest from my frontyard.
	415 pm A few minutes after the tornado warning was issued. View is looking west from Elk Creek Road. I still did not have a good view of the updraft base.
	428 pm View looking west-northwest from an elevated spot on Stagebarn Canyon Road, east of I-90.
	440 pm Well developed wall cloud.
	442 pm The storm seemed to move parallel to I-90.
	Impressive lightning. Note the forward flank precipitation to the right/north of the lightning.
	A tail cloud (tapering cloud pointing towards the right) joins the wall cloud from the right/north as cooler moist precipitation air is pulled into the updraft.
	450 pm The wall cloud was now west of me moving south. To the north of me a wall of precipitation with reports of hail. It was time to move south.
	529 pm View looking northwest from Skyline Dr. The storm still had a lowered updraft region but it seemed to be weakening.
	536 pm The storm headed straight south and stayed west of Rapid City while weakening.
	547 pm
	635 pm Just when I thought the storm was done, it briefly reenergized and started moving north. View is looking west from my backyard in west Rapid City. The radar loop (224 kb) shows a brief strengthening before finally dissipating completely.
	It also put down some impressive lightning. In fact, there was one "flang" (lightning so close that the flash and bang are almost simultaneous) that rocked the house.