Last week’s tornado in Brossard hit a top speed of 135 km/h, experts say

Article content

The tornado that swept through Brossard last week reached a top speed of about 135 km/h, according to the Northern Tornadoes Project.

It was the most significant of a total of four tornadoes that touched down in Quebec during heavy storms on Wednesday — uprooting trees, tipping over vehicles, ripping off roofs and blowing a shack across the street in Brossard’s industrial park.

Article content

The Northern Tornadoes Project was able to confirm the weather phenomenon as a tornado prior to visiting the scene thanks to a video posted on social media, executive director David Sills explained.

“But then we have to send out a team to get more information about how intense, how long, how wide — all of these things,” he said.

Article content

Article content

On the ground, the team was able to determine the tornado had been about eight kilometres long, 110 metres wide and measured on the low end of Category 1 on the Enhanced Fujita (EF) scale used to rank tornadoes. The scale ranges from 0 to 5, with 5 being the highest.

“Thankfully, it wasn’t any stronger than that,” Sills said. “We were thinking it could have been more serious than that given the video, but thankfully it was mostly a weak tornado and hadn’t caused as much damage as maybe as it could have.”

The group was able to confirm three other tornadoes had touched down in the province, in Boucherville, Lakefield and Cap Santé, all of which were categorized as EF0.

“In the Cap Santé case, there was some playground equipment that was tossed around and damage to a barn and that kind of thing,” Sills said.

In Boucherville, a roof lost a significant number of shingles.

“Just some weak tree damage in that area,” Sills said. “So it must have just been a really brief tornado that occurred there.” 

The team also investigated damage in St-Hippolyte, where there had been reports of a possible tornado, but they discovered it was actually a downburst, Sills said.

Article content

Toggle full screen modePrevious Gallery Image

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

Next Gallery ImageToggle gallery captions

All 13 Photos for Gallery

Function Not Available

Full Screen is not supported on this browser version.

You may use a different browser or device to view this in full screen.

OK

Article content

“With a tornado, you’ve got wind coming in towards the storm at the surface and then it ascends up into the updraft in the storm, in the area of the tornado. So it’s an in-and-up kind of motion with the wind, and it results in a long, narrow area of damage,” he explained. “With a downburst, it’s a down-and-out kind of wind. It actually comes out of the thunderstorm, hits the ground and spreads out, so it’s usually over a wider area. The trees or other damage indicators are usually downed in one direction, and it often occurs with heavy precipitation and hail.”

Northern Tornadoes Project was first launched as a pilot project in 2017 to locate tornadoes outside urban areas, which were missing from records since they’re not reported. It was so successful that the team decided to expand across the country.

“We managed to really increase the number of tornadoes that are being detected and documented across Canada,” Sills said. “Since we started, it’s about 100 tornadoes a year that we’re documenting, and before the project, the average was about 60. That’s a big increase.”

They hope to gather accurate numbers “to see if the patterns of tornado occurrence are changing in Canada, and if so, how,” Sills said. “Is climate change having an impact? … It takes a lot of data to be able to pull off of that, those kinds of trends.”

Article content

The 30-year average in Quebec is about 10.7 tornadoes per year, Sills said. There have been 13 so far this year and there were 10 last year, but 34 each in 2017 and 2018, “so it really does change a lot.”

“That’s typical across the country, too,” Sills said. “It just depends on what storms come through that year, if there’s drought, if there’s fire — there’s all kinds of different factors that figure into it. So there’s a lot of variability.”

Any tornado — even an EF0 — has the capacity to injure humans as a result of the debris they expel, Sills explained, so when there’s a warning, get inside and stay far away from windows and doors.

“We had a couple tornadoes last year where it was just rated EF0, so you wouldn’t think it was a big deal, but there was a two by four that was launched through the wall of a building,” Sills said.  “You don’t want to get in the way of the debris, no matter how strong the tornado is.”

kthomas@postmedia.com

Article content

Article content