An arctic air mass sprawling across the eastern, central and parts of the western U.S. on Monday will channel temperatures 20-30 degrees below already historically cold January averages and was poised to slam parts of the South with a disruptive winter storm.

Winter Storm Watch: The National Weather Service issues this when conditions are favorable for a winter storm to begin within 48 hours. Issuance usually occurs at 36-48 hours before the event is expected to begin.

The National Weather Service Jacksonville (NWS JAX) says mixed wintry precipitation is possible for the areas they've highlighted on the map. They say total snow accumulations of up to one inch and ice accumulations of around one to two tenths of an inch are possible.

Eight counties in New Jersey are under a winter storm watch, because of the possibility of heavy snow and dangerous road conditions