More than one million Americans and Canadians will be without power on Christmas Day as a major winter storm continues to batter North America.
When air pressure drops, a bomb cyclone forms, bringing snow, severe winds, and frigid temperatures.
Nearly 250 million people are affected, and at least 19 people have died as a result of the storm, which spans more than 2,000 miles (3,200 kilometers) from Quebec to Texas.
Thousands of flights have been canceled throughout the holiday season.
Montana, in the western United States, has been affected the hardest by the cold, with temperatures plummeting to -50F. (-45C).
In Minnesota, Iowa, Wisconsin, and Michigan, near-whiteout conditions have been recorded. The US National Weather Service (NWS) recorded “zero miles” visibility in Buffalo, New York.
Some residents in the Pacific Northwest ice-skated on icy streets in Seattle and Portland.
Coastal flooding has occurred in America’s north-eastern New England region, inundating communities and causing power lines to fall.
Even the typically milder southern states of Florida and Georgia are under strong freeze warnings.
California is the only region that has mostly avoided the cold weather, thanks to the continental mountain ranges that surround the Golden State.
The provinces of Ontario and Quebec bore the brunt of the Arctic blast in Canada.
From British Columbia to Newfoundland, much of the rest of the country was under extreme cold and winter storm warnings.
Several storm-related fatalities have occurred as a result of traffic accidents, including a 50-car pile-up in Ohio that killed four motorists. Four more people were killed in separate crashes across the state.
A dearth of snowplow operators was exacerbating travel problems across the country, with poor pay rates being blamed.
More than 100 daily cold temperature records might be tied or broken during the next three days, according to the NWS.