Strong storms developed near the Manitoba/Minnesota international border in the evening hours of August 12th 2015 and became supercellular quickly. After seeing several large wall clouds and broad rotation we called in a report to the National Weather Service since we were the only ones on this storm. They issued a tornado warning on it several minutes later after we saw a long white funnel cloud. We saw multiple funnels & wall clouds after that but no ground rotation. We did experience significant straight line winds in the area of 100+ km/h near Thief River Falls and large hail bigger than gold balls and we saw some minor damage in town. This video is sped up 20x and 8x its original format to see the rotation.