A massive arctic air mass will push into the United States next week, resulting in temperature departures as much as 15 to 20 degrees below normal from the Great Plains to the Eastern Seaboard. Across the northern Plains and Upper Midwest, it will drop to 30 below during the overnight hours. Minneapolis may simply stay below zero for a couple of days, and Chicago may have temperatures no higher than the single digits.

An unknown at this point is a possible storm that could have impacts from the western Plains to the East Coast. The tentative track and timing of the storm are shown. We'll know more about this threat as time goes on. For now, let's just say it could turn into a significant snow-producer across the South and East.

Story By AccuWeather.com Senior Meteorologist John Kocet.