The National Weather Service warned that severe winter conditions—triggered by an Arctic blast—could persist over the weekend into Monday.

Biting cold conditions – below-freezing in some areas – will sweep across a large swath of the United States Sunday while heavy, record-breaking lake-effect snow makes post-holiday travel “treacherous” and nearly “impossible” in parts of the Great Lakes region.

Bone-chilling Arctic air gripped much of the eastern United States on Saturday, while lake-effect snow threatened to disrupt post-holiday travel in parts of the Great Lakes region.