A massive winter storms is leaving over one million Americans and Canadians without power on Christmas Day.
When atmospheric pressure falls, a bomb cyclone occurs, bringing snow, strong winds, and subfreezing temperatures.
The storm, which stretches from Quebec to Texas, has killed at least 19 people and affected nearly 250 million.
Thousands of flights were canceled over the holidays.
Montana, in the western United States, is the hardest hit by the cold, with temperatures reaching -50F. (-45C).
Minnesota, Iowa, Wisconsin, and Michigan reported near-whiteout conditions. Buffalo’s NWS reported “zero miles” visibility.
On the frozen streets of Portland and Seattle, some locals in the Pacific Northwest ice skated.
In the northeastern New England region of the United States, coastal flooding has been observed, inundating communities and bringing down power lines.
Hard-freeze warnings are in effect even in Florida and Georgia, two typically milder southern states.
California, protected by continental mountain ranges, is the only state that has avoided the cold.
The Canadian provinces of Ontario and Quebec were experiencing the worst effects of the Arctic blast.
From British Columbia to Newfoundland, a large portion of the rest of the country was under winter storms and extreme cold warnings.
Four people were killed in a 50-car pile-up in Ohio during the storm. Another four died in state crashes.
A shortage of snowplow operators was causing travel problems across the country, which was being blamed on low wages.
The NWS says that over the next few days, more than 100 daily cold temperature records could be tied or broken.