How an icy breath of ‘freezing fog’ created a mystical scene in the South Matthew Cappucci Rime ice in Alabama on Wednesday morning. (Tyler Corvin/Instagram @CapturingCorvin) Parts of the South awoke to a display of jagged rime ice Wednesday morning, the result of “freezing fog” that descended across the area. Alerts were issued in Alabama, Georgia, Tennessee, Southwest Virginia and parts of the Carolinas, where the National Weather Service advised of low visibility and possible slick roads. How this fascinating, needlelike ice formed in the D.C. region Freezing fog is exactly what it sounds like fog that coats objects on the ground with a slippery layer of ice. It forms at temperatures below freezing, when moisture in the air takes the form of supercooled water droplets but remains in a liquid state.