Millions of Americans face an artic blast, including the first-ever blizzard warning for parts of the Gulf Coast.

Around 40 million people, primarily across the southern US, were under some type of weather hazard, March Chenard, a meteorologist with the NWS, told BBC's partner CBS News. Another 170 million people from the Rockies to points eastward were under an extreme weather warning or cold weather advisory.

Winter storms closed schools, snarled flights and put millions of residents on alert across parts of the Deep South and south-central United States.