A few nights ago, my wife and I were driving east through Northbrook (IL) as a storm was heading our way from the south. Since we were moving and had no clear opening to the south, it was difficult to get any pictures of the impressive system. As we kept driving and the system kept moving and came to us. I had the chance to get some quick shots of a severe storm crossing the road in front of us. The sky went from bright to almost total darkness in a matter of minutes.