This animation of GOES-8 visible imagery shows the development of convection that produced large hail and damaging winds across parts of North Dakota and Minnesota on 08 August 2001. Thunderstorm downburst winds gusted to 114 mph at Grand Forks Air Force Base ND at 01:16 UTC (8:16 PM Central time), 101 mph at Grand Forks ND (KGFK) at 01:26 UTC (8:26 PM Central time), and 79 mph at 01:56 UTC (8:56 PM Central time) at Crookston MN (KCKN). Well-defined overshooting tops were evident on the visible imagery.