Snow and dangerous ice spans 1,300 miles of the US and is still pushing east. It will impact more than 2,000 miles from Texas to New England through

The impending winter storm is set to begin across the south-central U.S. on Friday.

More than 146 million people across portions of at least 37 states were under a cold weather advisory as of Friday afternoon. Another 86 million people in 21 states were under a winter storm warning. Nearly 17 million people in nine southern states were under an ice storm warning.

The storm stretches from New Mexico to the South to the Northeast.

This index, from NOAA's National Weather Service, attempts to scale the impacts from winter weather, taking into account factors such as snowfall, accumulated snow on rooftops, ice accumulation, the potential for a flash freeze, and blowing snow. Not all factors are in play in a given winter storm.

US Weather LIVE Updates: elta Air Lines said on Saturday it made additional flight cancellations for Atlanta and along the US East Coast, including at its hubs in Boston and New York as it continued to adjust schedules due to winter storm Fern.