June 18th was an incredible day in South Dakota! Superb moisture, instability and shear was moving northwest from Nebraska and pooled along a cold front. By mid afternoon numerous storms formed along the boundary and merged into a squall line. This was a bit disheartening to see, but we stayed with the tail end and eventually, as the better shear arrived, supercells formed and produced at least 8 tornadoes we witnessed including a couple of strong tornadoes near Wessington Springs, SD. These storms were amazingly electrified and had great structure as well. We had two different times when we had 2 tornadoes on the ground together. The final set of twins were the last two tornadoes of the event and very photogenic. What an amazing 3 day period we had, were we witnessed nearly 15 tornadoes!