NEW YORK - Millions of Americans are preparing for the coldest weather they've ever experienced as an arctic blast sweeps much of the country this week.

The National Weather Service says that much of the U.S. will see the coldest temperatures in almost 20 years, with many cities dropping as low as 50 degrees below zero.

New record lows are even possible in Minnesota where the current record, set in 1996, is 64 degrees below.

The gripping cold and ice has already stranded travelers in some cities with buses and flights being delayed or canceled.