It was an intimidating sight watching this monster barrel towards me. It’s amazing how something can be so beautiful and so destructive at the same time. Within minutes the sky changed from bright and sunny to black and the quiet turned into a roaring wind. This supercell first formed in Montana, before charging southeast along the Black Hills. Enhanced wind shear next to the mountains helped sculpt the clouds into this ominous structure. 2 tornadoes were reported, the first knocked down swaths of forest, while the second destroyed buildings farther east. Experts disagree on why exactly some storms appear green. But it is a good indication that a storm reaches high into the atmosphere and contains much precipitation, which often includes hail. At the time of this shot hail stones 3-4” in diameter were falling just a few miles away in downtown Rapid City. As much as I wanted to stay and time lapse this scene, I continued to flee south instead out of the damage path. I've found my windshield to be more effective when it stays in one piece.