Dangerous ice storm sweeps parts of southern US

Nearly 38 million people are under a winter weather alert in south-central parts of the US, spreading from Tennessee to Texas.

A mix of freezing rain, sleet and bitter cold air has already hit parts of the region and is expected to last until mid-week.

More than a 1,000 flights have been cancelled, with airports in Texas particularly affected.

Forecast suggests "treacherous travel conditions" over the next few days.

On Tuesday morning, the National Weather Service predicted up to over a half-inch of ice to accumulate on the roads in Austin, Dallas, Little Rock and Memphis.

"In addition to potentially hazardous travel conditions, this amount of ice will likely lead to tree damage and scattered power outages across the hardest-hit regions," the agency added.

Several schools in Texas have been closed in anticipation of the storm.

This weather phenomenon is caused by an arctic cold frontal passage making its way south, where it is being confronted with warm and moist air from the Gulf of Mexico.

The result is wintry precipitation that is expected to drape over the region, the NWS said. The agency also expects heavy rain and scattered flash floods to hit parts of the Deep South and Southeast by midweek.

Meanwhile, the cold air mass will also impact the central and western regions of the US, where wind chills will plummet temperatures well below average to -40F (-40C). Temperatures in New England are also expected to drop to -30F (-34C) and all the way down to -60F (-51C) near the Canadian border.

As of Tuesday morning, more than 980 flights out of the US have been cancelled, impacting major airlines like Delta, American, United and Southwest, according to flight-data tracking website FlightAware. All the airlines have allowed passengers to rebook their flights without paying extra fees.

Dangerous travel conditions have already affected drivers in Texas on Monday, with car crashes reported in Arlington due to the ice storm.

"Bridges and overpasses are considered treacherous," said Arlington Chief of Police Christopher Cook while attending to a major crash in the area. He urged motorists to slow down and drive carefully.

Two years ago, freezing rain conditions in Texas led to a 130-car pile up on Fort Worth highway that killed six people and injured several others.