Started the day in North Platte, NE and got a late start heading north with Scott Blair, Lauren Hill, and Chris Hill. We stopped for lunch in Valentine, NE, meeting up with Amos Magliocco who joined the rest of the convoy for the day. After a a stop in Murdo, SD to reassess the situation, it became clear we needed to go north and east as the better moisture axis had shifted. Extreme CAPE values had developed by the mid afternoon across north-central into eastern SD with a warm front lifting across portions of northern SD. We were initially skeptical of the day as little cu had developed to this point. However, heading east out of Murdo, we finally noticed the first stout cu developing between Gettysburg and Selby, SD. Heading north on Hwy. 83, we observed convective initiation across this area, which rapidly became supercellular. We took Hwy 20 east then Hwy 47 north to get into position. While on Hwy 47, a stout lowering was observed which quickly showed signs of rapid rotation. Soon the circulation tighten and a cone funnel developed. The first tornado developed just west of Hwy. 47 characterized by an initial cone funnel with debris fan below. The tornado then transitioned into a stove pipe shape then back to a more broad cone with debris whirl beneath as it crossed Hwy. 47. We jumped north on Hwy 47 then east on Hwy 12 to stay ahead of the tornado. As the circulation crossed Hwy 47 and then Hwy 12, it widened and again fully condensed, becoming a wide cone. As we observed the tornado along Hwy. 12, the RFD precip soon cleared revealing a white meso with grayish cone beneath on the south side of the circulation. We continued to move east on Hwy 12 to Bowdle and then north again on Hwy. 47. At this time, the tornado transitioned to a large wedge with an intense, rapid ground circulation. This was by far the most intense tornado I have ever observed. As the tornado traversed the field, it crossed a line of metal power transmission towers, which were toppled over. The RFD was quite intense at our location, occasionally  wrapping sheets of rain. It eventually  crossed Hwy. 47 engulfing a radio/cell tower while becoming more rain-wrapped. We decided to continue east on Hwy12 again when a second tornado developed north of the road. This tornado took on a stove pipe appearance before becoming an elephant trunk and then dissipating. We continued east on Hwy12 before turning north again at Ipswich. We positioned ourselves northeast of the meso where our contrast would be best given the larger amounts of precipitation that was beginning to wrap around the back side of the storm. There we observed a third tornado, which was a cone with several tentacles extending to the ground. This circulation soon became rain-wrapped, then re-appeared and became rain wrapped again. We let the low level circulation pass south of our location and headed south on the back side of the storm. With day light winding down and the storm becoming increasingly HP in nature, we decided to get ahead of the storm to get some structure shots. We ended the day in Aberdeen with some dinner before heading south for the next day.