Bitter cold and heavy snow may stymie holiday travel plans.

A massive cold front has blown south from Canada into the United States, bringing with it both major temperature drops and severe snowfall. As this front moves south through the US, winter conditions are expected to worsen throughout parts of the country, making travel potentially life-threatening in its worst spots.

Currently, the front is at its worst in Washington state. According to the National Weather Service, “an approaching storm system and surge of moisture will lead to widespread snow to impact northern and western portions of The Evergreen State.”

“Snow is likely to fall across the lowlands as well and could be heavy at times, leading to dangerous travel conditions,” it said.

Idaho, Montana, and Wyoming are expected to receive at least a foot of snow in the next day, if not more. This snow is being accompanied by a 60 mph, minus 40 wind chill that could potentially cause frostbite with just ten minutes of skin exposure.

“With such a large and powerful storm system impacting a majority of the nation during one of the biggest travel weeks of the year, it is imperative that travelers check the latest forecast before venturing out,” the National Weather Service warned.