After chasing storms for most of the afternoon, I ended the day by watching this storm recede into the distance over the sand hills near Torrington. The hanging pouches in the sky are known as mammatus clouds. They are somewhat rare and this was the best display I've ever seen. Mammatus clouds typically form underneath the anvil of a severe thunderstorm and are caused by sinking cold air. This storm was a cyclic supercell which produced multiple tornadoes in western Nebraska. Lightning was very frequent and I caught this bolt in one of the time lapse frames.