HOUSTON, United States

Blizzard conditions are expected across much of the US during the Christmas holidays in what weather experts are forecasting to be a "life-threatening" bomb cyclone.

Heavy snow, freezing temperatures and strong winds are expected to put most of the country in a deep freeze, from the states of New York to Michigan to Nebraska and Washington and Texas and Florida.

"Records will be challenged in some areas," meteorologist Alex DaSilva told the USA Today newspaper. He said temperatures could drop up to 30 degrees below normal in many regions.

"It's a measure of rapid strengthening of a storm, and it does look like the storm will achieve that ‘bomb-cyclone' status because it's going to strengthen pretty rapidly," added DaSilva.

A bomb cyclone is when a storm's central pressure drops at least 24 millibars within 24 hours.

The brunt of the winter storm is expected to begin Thursday and last through the weekend with an incoming Arctic front slamming the US with blizzard conditions and up to 2 feet (61 centimeters) of snow in some states that could halt travel for millions of Americans.

The National Weather Service called the system "life-threatening' and issued a winter storm watch for more than 40 million people in the northcentral US. It also issued winter storm warnings, wind chill warnings and winter weather advisories across parts of the Midwest and Pacific Northwest

"Heavy snow, blowing snow, & snow squalls across the Northwest mountains & Rocky Mountain Front. Snow, locally heavy, to sea level across much of western WA (Washington state). Bitter wind chills from Northwest to S. Plains (southern plains). Showers/storms in FL (Florida) and Southeast coast may produce localized flooding," it tweeted.

The deep southern states of Florida and Texas are also expected to be hit with freezing temperatures.

Major US airlines are already issuing travel waivers for passengers, anticipating the chaos that is expected to cancel flights due to the winter storms.