Good question. I brought this up to my wife when Frances hit and there was still debris from Charley in the greater Orlando area. I'm worried because in Gainesville, we've got debris EVERYWHERE. I'd assume that it doesn't take much to lift debris off the ground. BUT, I noticed that during Frances, the debris thrown off the trees early in the storm was never picked back up even after several hours. Maybe it was because that debris was wet, or tropical storm force winds weren't enough. Anyone else have anything to offer on this?