As two storms organize and bring precipitation into freezing air at the surface, that makes us concerned about the threat for freezing rain from Saturday night into Sunday. One of the ingredients that will allow for the low-level cold is this phenomenon called, cold air damming. In a typical setup of cold air damming, you have winds coming at a direction that contains a northerly vector due to high pressure either north or overhead of the Appalachian Mountains. Cold air will therefore flow southward along the eastern side of the Appalachians, and that cold air associated with this cold air damming can get as far south as northern Georgia in typical situations.
So from northeastern Georgia through central Pennsylvania. Notice how all of these locations are just east of the Appalachians. Meanwhile in the Appalachians, they will receive snow. So late-Saturday night or really early Sunday morning, freezing rain is expected to break out and last for several hours in northeastern Georgia into the western Carolinas. We don’t think Atlanta will deal with any icing, but a city like Charlotte has the risk for at least a brief period of freezing rain.
During the day Sunday, the freezing rain will become more widespread. During the morning hours, western Virginia and the western Carolinas will likely deal with icing conditions while it clears out of Georgia. Cities that may be impacted include Charlotte, Roanoke, and Greensboro. Then in the afternoon, the freezing rain is expected to move out of the Carolinas while continuing in western Virginia. It will also move into western Maryland and central Pennsylvania. There is the chance Washington, D.C. experiences a brief period of freezing rain, but based on how this winter (or non-winter) has been, the odds are looking low.
By the evening hours of Sunday, warmer air and rain will takeover, therefore ending the freezing rain threat for everyone. Unfortunately, roads will be slick, especially in the Southeast, so avoid travel if you can this Super Bowl Sunday.