More Canadians are in the path of tornadoes — but don't always know they're coming

What On Earth23:52More Canadians are in the path of tornadoes — but don't always know they're coming

Tornadoes are touching down across the country, often without specific warnings to residents in the storm's path, experts say.

Dave Sills, executive director of Western University's Northern Tornadoes Project (NTP), says they've found that Environment Canada "hadn't been doing very well" at alerting people of tornadoes that touched down across the country between 2019 and 2021.

"About 70 per cent of tornadoes had no tornado warning on them — and that included most of the EF-2 tornadoes that we have in our database," he said, referring to tornadoes that can cause "considerable damage" including tearing roofs off houses.

Tornadoes are less common in Canada than in the United States, where they're a regular sight in "Tornado Alley" — the region stretching north from northern Texas to South Dakota. U.S. data indicates that tornadoes there are steadily shifting eastward, closer to more densely populated regions, the researchers say.

In Canada, tornadoes most commonly occur in southernmost Saskatchewan, Manitoba and Ontario, but can also occur in southern Alberta, southern Quebec and New Brunswick. NTP data suggests peak tornado season in southern Ontario is now more likely later in the summer.

While the project's data don't indicate there are more tornadoes occurring in Canada — or that climate change is affecting their frequency — population growth and the expansion of suburban areas mean they're increasingly in the path of homes. 

"Everybody sees what happens in the U.S. and thinks, 'Well, that doesn't happen here.' But in our peak months between June and August, anything that happens in the U.S. is possible here," said Sills.

Environment and Climate Change Canada, the federal department responsible for the country's meteorological service, says while alerts are not issued for every tornado, they would have been published for many of the thunder and wind events that spawned them.

"We may mention in a severe thunderstorm warning that there is a risk of tornado," said Ken Macdonald, executive director of national programs at ECCC.

"Weather radar is a great tool for the forecaster, but it doesn't actually see tornadoes. It sees the thunderstorm and can see that there may be rotation that could produce a tornado, but it doesn't actually tell you that there is a tornado."

'Like the ground was curling up towards me'

Tornados can come on suddenly and with few warning signs, something James Blacksmith knows first hand. He didn't get any kind of alert when a tornado formed as he was driving across Manitoba's Highway 83.

The skies showed no indication of an impending storm, Blacksmith told CBC Radio. It was only when the wind suddenly picked up that he knew there was trouble.

"Something hit the roof of my Jeep. So I thought it was going to start to hail, so I pulled into a farmyard," he said. "I pulled in under big pine trees … and there was a white truck that pulled up beside me."

The next thing he knew, a tornado had formed, touching down near Scarth, Man. "It looked like the ground was curling up towards me, like a wave," he said.

A tree fell onto Blacksmith's vehicle, pinning him in place. The neighbouring truck was pulled into the tornado's vortex. 

The truck was flung through the air, killing its two teenage passengers. Blacksmith emerged with injuries that continue to affect him today.

"The tree that fell kind of saved my life, I guess. It held me down for a while," said Blacksmith.

Environment Canada classified the tornado as EF-3, with winds of up to 260 km/h, after initially assessing it at EF-2.

Canada's vast geography makes forecasting tornadoes difficult. Large swaths of uninhabited land and plenty of forested area mean that many of the storms go unnoticed.

"Not every situation where a severe thunderstorm produced some wind damage, for example, would we go out and investigate and determine what was that? A tornado or was that wind damage?" said Macdonald. "We have not been able to put the resources into doing that."

Damage from an EF-0 tornado, the lowest-severity tornado possible, may look similar to a strong wind event, like the derecho that swept over Ottawa last May, he added.

Improvements to forecasting system ongoing

That's where the Northern Tornadoes Project comes in. The project's research team has been tracking the number of tornadoes across the country using historical data, high-resolution satellite imagery and eyewitness reports.

In addition to documenting as many tornadoes as possible, their work uncovered a previously unknown major twister that hit Quebec in 2017.

"There's going to be more impacts just because of population growth and expansion of our suburban areas," said Greg Kopp, an NTP researcher and the ImpactWX Chair in severe storms engineering at Western University in London, Ont.

"And so to pull all of that apart, we really need to do this — these detailed studies — to try to find everything so we have a good baseline to compare against."

What am I going to do when I get that warning? Where am I going to go?- James Blacksmith

Macdonald said that Environment Canada is working with Sills and Kopp to better understand how tornadoes are impacting Canada. Ongoing upgrades to the country's weather radar systems will also help forecasters better predict the chance of a tornado, he added.

But when it comes to alerting the public, Macdonald notes the agency aims to strike a balance. Sending notifications for uncertain weather events that don't materialize could reduce confidence in the system, he said.

"We looked at just one example of a situation this past summer where there was a tornado formed [in Ontario]," he said. "There might have been on the order of 25 significant thunderstorms scattered all over the place. One of them produced a tornado."

Blacksmith admits that he's unsure an alert would've done much good given he had few safe locations to turn to.

"What am I going to do when I get that warning? Where am I going to go? I don't know what's happening," he said.

Calls for update to building code

With growing knowledge of the frequency and potential impact of storms, Sills and Kopp say it's time to reconsider how homes are protected against the threat of tornadoes.

Hurricane straps — metal brackets that secure the roof of a house to its walls — are one option that isn't yet required for most home builds in Canada.

"We've discovered that the weakest link in the structure is actually the roof being fastened to the walls," said Kopp.

According to Kopp, there is resistance to mandating hurricane straps due to the added cost. There are also questions about the effectiveness of designing for tornadoes. But he adds that there is evidence that hurricane straps can protect a home's inhabitants and the community more broadly.

"That little piece of metal is strong enough to hold the roof to the walls and in a tornado up to EF-2."

In a statement, the Canadian Commission on Building and Fire Codes says that hurricane straps are required in seven regions — in parts of Alberta, Newfoundland and Northern Canada — that experience "higher wind loads." 

It continues, adding that climate change adaptation is a "policy area for attention" for the 2025 and 2030 editions of the National Building Code, a model code. Building codes are a provincial and territorial responsibility.

Kopp says he's seeing positive moves toward implementing hurricane straps. For example, he says a major home builder in Barrie, Ont. — a city hit by a devastating tornado in 2021 — is adding them to new homes. 

"We need to do it because it's the right thing to do," said Kopp.

"Let's just solve this problem with a simple solution, which is put these things in and we'll be good to go."