These guys decided to head north from Rapid City where some storms north of the hills looked promising.  Even though Matt took nearly 2 hours to get ready (no doubt powdering his face), they managed to catch up to this storm north of Sturgis, SD.  Bear Butte is in the background.

A short time later…and a second storm further to the northwest.  There is quite a bit of rain and hail off in the distance, and the lower hanging cloud likely denotes the front of the storm’s outflow.

…same storm some time later, now with a very apparent shelf cloud.  This is the leading edge of the gust front.  The location is north of Bear Butte on Hwy 79 approximately 2 miles south of Castle Rock, SD; as this passed over winds got fairly strong.