At least 46 million people were under a winter storm warning as of Thursday as the storm spreads along the Gulf Coast Friday, according to the weather service. The storm should weaken by Saturday, bringing lighter snow between 1 and 3 inches to parts of the Northeast, the Mid-Atlantic and the Ohio Valley before exiting off the Carolinas.

The wintry wallop comes as a blast of Arctic air will invade much of the Midwest, Great Lakes and northern United States for roughly a week.