Bomb cyclone: What to know as Canada faces a stormy Christmas weekend

Click to play video: 'Severe winter weather ruins some Christmas plans'
Severe winter weather ruins some Christmas plans
WATCH: Intense winter weather has wreaked havoc with the busiest travel period of the year, grounding flights and disrupting travellers' holiday plans. Neetu Garcha reports on the heartaches and headaches some people are experiencing – Dec 25, 2022

A massive cross-country winter storm is unleashing destructive winds and heavy snow, causing hundreds of airline cancellations and power outages from Canada’s coast to coast.

The “bomb cyclone” that blew in on Thursday night is expected to stick around during the holiday weekend.

Read more: Winter storm slamming Canadians will be ‘a big one,’ 320K already without power

Here’s everything to know about the storm.

What is bomb cyclone?

Click to play video: 'Massive winter storm snarls holiday plans'
Massive winter storm snarls holiday plans

According to Global News chief meteorologist Anthony Farnell, most of Ontario and southern Quebec have met the threshold of a “bomb cyclone.”

Farnell said the storm is arriving from the U.S. Midwest.

Story continues below advertisement

A front of cold air is moving down from the Arctic, sending temperatures plunging.

As the Arctic air pushes into the warmer, moister air ahead of it, the system quickly develops into serious weather — into what’s known as a “bomb cyclone.” It’s a fast-developing storm in which atmospheric pressure falls very quickly over 24 hours. Whether a storm qualifies as a bomb cyclone depends on how fast the pressure drops.

Although Friday will see mild temperatures as the system moves in with rain, Farnell said earlier this week that it will be replaced with much colder Arctic air and snow as Friday progresses.

In the United States, the National Weather Service is calling the winter storm a “once-in-a-generation type event.”

Story continues below advertisement

It has turned deadly in the U.S., where at least six people have died in vehicle accidents during the treacherous weather, Accuweather has reported.

What are the impacts?

Environment Canada issued weather advisories and special statements for much of the country earlier this week.

The storm will be impacting pretty much everyone as it moves from Western Canada and into Ontario, Quebec and Atlantic Canada.

Peter Kimbell, a warning preparedness meteorologist with Environment Canada, told Global News it will be a multi-day weather event with fluctuating temperatures that could cause treacherous driving conditions.

Click to play video: 'What Canadians need to know about extreme winter weather storming across North America'
What Canadians need to know about extreme winter weather storming across North America

Kimbell said Friday will be the worst day for travel, particularly for Ontarians, and that is why the weather agency is issuing the alert early as the Christmas holidays approach.

Story continues below advertisement

About 320,000 people across the country are already facing power outages, according to an outage tracker from the generator company Generac, which aggregates data from providers across the country.

And these outages aren’t going to end any time soon, Farnell warned.

Read more: Winter storm power outages may not be fixed until Christmas Day — ‘A difficult go’

“You shouldn’t expect (power) back until the earliest, I’m thinking on Sunday. That’s Christmas Day. Because crews just cannot get out in blizzard conditions, they can’t deal with the cold,” he said in an interview with AM640 Toronto, a radio station owned by Global News’ parent company Corus Entertainment, early Friday morning.

Air travel has also been severely impacted due to extreme weather conditions. WestJet has “proactively” cancelled flights at airports in Ontario, Quebec and British Columbia.

Air Canada and Flair Airlines have also cancelled a number of their scheduled flights.

How common are such storms in Canada?

“We may only see one of these storms every five or 10 years,” Environment Canada meteorologist Mitch Meredith told The Canadian Press on Friday. “I’ve only seen a couple of storms like this in the last 20 years.”

Story continues below advertisement

Kimbell told Global News on Dec. 20 that winter storms during the wintertime are expected and “nothing unusual.”

“This one this weekend will be particularly severe with a very deep central pressure of very strong winds across Ontario, so this is going to be a particularly dangerous storm, but I don’t think it’s a precursor to the winter,” Kimbell said.

But “this one’s going to be a big one and there’ll be a lot of impact for a lot of people,” Kimbell said in an interview with Global News.

Come New Year’s Eve, many parts of Canada will see temperatures above seasonal, Farnell said.

Read more: Holiday storm looms as winter kicks off in Canada. What can we expect?

That trend will probably last through the first half of January, before shifting to a “very cold” end of January and a potential start to February as well.

This season will also be the third-consecutive La Niña winter Canadians have experienced, Farnell added. La Niñas develop over the Pacific region due to colder-than-normal water temperatures and impact the weather pattern across Canada.

“Very rarely have we had three years in a row of La Niña,” he said, adding that La Niña winters play out with similarities to previous ones; 2022 started with really cold weather across the country.

Story continues below advertisement

— with files from The Associated Press, The Canadian Press and Global News’s Rachel Gilmore, Aaron D’Andrea and Gabby Rodrigues 

Sponsored content