Guys, I saw a quasi-dust devil today while on a run. I was deep in this forest preserve, with a friend, when we noticed leaves whipping around us. We turned to our right and there was a legitimate cone of dust maybe half a foot wide and a foot tall zipping around the prairie next to us, a mere 20' away. No clouds overhead, and the whole area was still smoldering for a controlled burn, maybe the heat caused it. It was really cool but short lived, it cross the path and died out in less than a minute.