(Montreal) It is not one, but two tornadoes that would have touched down during the passage of a system of violent thunderstorms last Thursday in Quebec, according to researchers from Western University, in Ontario.
In addition to the tornado already confirmed by Environment Canada in Mirabel, experts from the Northern Tornadoes Project (NTP) claim to have found evidence of another weak tornado that took place near Saint-Thomas, in Lanaudière.
In an article published Wednesday on their site, the researchers explained that this second tornado received the lowest intensity rating.
“An NTP ground and drone survey was conducted on July 16-17, 2023 and documented damage to trees, as well as damage to two barns and the roof of a house. A visible tornado path through crops was also observed,” the researchers said.
As a result of their analyses, the estimated maximum wind speed was set at 130 km/h, the path length at 6.61 km and the maximum path width at 200 m.
In the case of the other tornado, which was reported by a weather observer at Mirabel Airport, it caused no damage according to the NTP.
Asked to comment on the NTP sightings, Environment Canada meteorologist Peter Kimbell said the federal weather agency will not release a strength rating for the tornado in Mirabel and cannot confirm the second tornado in St. Thomas.
Environment Canada, however, does not dispute the conclusions of the Northern Tornadoes Project.
Also, in addition to the two tornadoes, the NTP has listed five locations in Quebec where downbursts — a phenomenon where descending air from a thunderstorm causes intense winds when it hits the surface — occurred during the storm.
In Lanoraie and Sorel-Tracy, damage to trees and the roofs of several structures was reported. The NTP assessed gusts of 150 km/h in this sector.
Similar phenomena have also been recorded near Saint-Jérôme, Sainte-Anne-des-Plaines and Sainte-Sophie, as well as in Saint-Anicet.
Last Thursday, the steamroller composed of violent thunderstorms moved over a distance of about 450 kilometers between the south of Ottawa and Sainte-Anne-de-la-Pérade, halfway between Trois-Rivières and Quebec.
All affected areas received rainfall amounts varying between 50 and 90 millimetres, which caused sewer overflows and extensive flooding in several municipalities.
Another tornado has also been confirmed by Environment Canada south of Ottawa in connection with this system.