A 'Bomb Cyclone' Threatens to Make Holiday Travel a Nightmare A powerful winter blizzard is expected to paralyze much of the U.S. with heavy snow, high winds, and freezing temperatures.

Santa Claus might want to sit this Christmas out.

Meteorologists are warning that a massive winter blizzard will hit a large portion of the U.S. in the next few days. Described as a "bomb cyclone," the storm will bring heavy snowfall and bone-chilling temperatures, disrupting travel plans for millions of Americans.

The terrible weather couldn't have arrived at a worse time.

According to the Automobile Association of America, 112.7 million people will journey 50 miles or more away from home from December 23 to January 2 this season, an increase of 3.6 million people from last year.

But as of Wednesday night, 200 million people were under extreme weather alerts as the storm moved eastward toward the Plains, Midwest, and Great Lakes. The storm will also bring strong winds and a possible flash freeze to parts of the Midwest, East, and South.

Winter Storm Warnings have been issued all the way from Denver to Buffalo.

Already, more than 484 U.S. flights scheduled between Wednesday and Friday have been canceled, according to the flight-tracking service FlightAware.

Related: The Rise in Natural Disasters Is Putting More Businesses at Risk. Are You Protected?

What is a bomb cyclone?

A bomb cyclone happens when atmospheric pressure at the center of a storm drops rapidly to about 1 [millibar]every hour for 24 hours, causing freezing temperatures, heavy winds, and heavy snow.

"It's called a bomb cyclone because a low pressure (or cyclone) undergoes 'bombogenesis,' which refers to the quick rate at which the low pressure develops," Mike Bettes, a meteorologist for The Weather Channel, told CBS News.

The combination of life-threatening temperatures and strong winds also leads to dangerous wind chills.