The polar vortex's blast of Arctic air from Canada brought the season's coldest weather to the majority of U.S. The vortex is forecast to provide frigid weather as it continues to bring sub-zero temperatures to the Midwest, Mid-Atlantic and plunge deep into the South.

A blast of Arctic air is set to cover much of the United States with temperatures below freezing starting on Friday and into next week, impacting millions of Americans in nearly all of the contiguous states.

Despite a cold start to the day, most of the U.S. will experience seasonably mild temperatures on Thursday. However, dangerous changes are on the way as a polar vortex tightens its grip on the nation as sends temperatures tumbling below freezing starting this weekend.

A polar vortex is slated to sweep most of the continental US bringing winter storm warnings and a hazardous freeze to millions.