Canada’s Tornado Alley may move from Prairies to Ontario-Quebec, researchers warn
The tornadoes that swept through the suburbs of Ottawa and near Montreal on Thursday indicate a growing concern for researchers.
Preliminary data trends suggest Canada’s most densely populated zone — in Ontario and Quebec — could become the country’s epicenter for twisters, with increasingly devastating consequences.
“What we’re seeing is consistent with climate change projections,” David Sills, executive director of the Northern Tornadoes Project (NTP), told CBC News. He pointed to information gathered in recent years by the team at Western University in London, Ont.
Canada’s Tornado Alley, long believed to be largely in the Prairies, appears to be moving east, where millions of people still live.
“We have a lot more work to do collecting data to make sure those trends are robust,” Sills, a former Environment Canada tornado researcher, said in an interview. “But it sure looks like that’s the case. And that’s not good news, [with] many residents in this area of Windsor [Ont.] to Quebec City.”
Canada reports more tornadoes than any other country except the US
Sills’ NTP team is trying to get a better picture of the number of twisters hitting Canada by compiling the most comprehensive database the country has ever had.
When they began tracking the data, they identified 70 tornadoes in 2017. As their work expanded and the team received more reports from the public, the number grew to 118 confirmed tornadoes in 2021 and another 117 last year.
“We’ve only noticed in the work we’ve been doing since 2017… there seems to be a lot of tornadoes happening in eastern Ontario [and] southwestern Quebec, and there’s not that much going on on the prairies,” Sills said.
A team from CBC News recently followed a team from the NTP in their investigation of a suspected twister in rural Tweed, Ontario, northwest of Kingston. By analyzing weather data, then mapping damage from above using a drone and inspecting fallen trees and other debris on the ground, the researchers have closed the area had been hit by two tornadoes – both rated on the Enhanced Fujita Scale (EF) as an EF-0.
For comparison: the tornado which destroyed several homes in central Alberta on Canada Day was considered an EF-4, one of the most powerful twisters in the nation’s history.
An EF-4 signals wind speeds between 270-310 km/h. The EF scale comes in at 5, with even high winds and “massive devastation,” according to it Public Safety Canada.
Canada’s deadliest tornado swept through Regina in 1912. The EF-4 killed 28 people and made 2,500 homeless. If such extreme weather becomes more common in Central Canada, it poses an even greater risk, experts say, with some 18 million people living between Windsor and Quebec City.
Aaron Jaffe, an NTP researcher who led the team on the ground in Tweed, warned against minimizing twisters only classified as EF-0 or EF-1.
“It only takes one tree to fall in the house or cottage and then you have significant damage,” he said.
Build resilience
Part of the NTP’s work is to build Canada’s resilience to tornadoes.
“Knowing more precisely where they are happening will allow us to come up with adaptation strategies that make a lot more sense,” said Greg Kopp, a professor of engineering at Western University.
Kopp said Canadian building codes should be updated to reflect the growing risk of tornadoes, and that homebuilders should consider small investments to mitigate a tornado’s potential impact.
“Twenty years ago, when we started talking about this, the only response we ever got was, ‘You’re crazy,'” says Kopp, who serves as NTP’s principal investigator.
He said simple additions to new construction, such as hurricane straps or roof clips, can help prevent major damage and cost only a few hundred dollars. The tiny connectors can hold roofs even in the event of an EF-2 tornado, Kopp added.
