Researchers with Western University’s Northern Tornadoes Project (NTP) say they have confirmed that two tornadoes touched down within London’s city limits on Saturday as a destructive and deadly thunderstorm rolled across southern Ontario.
The storm, which Environment Canada has said involved a derecho — a rare widespread windstorm associated with a line of thunderstorms — uprooted trees, damaged buildings, toppled power lines and left thousands in the dark for hours in the city, including some for several days.
On Friday, Western researchers revealed that two preliminary EF1-rated tornadoes were behind some of the damage seen in London’s northeast, including at the airport, and in the city’s far south end.
“Both tornadoes occurred within minutes of each other…. They may even have been occurring at the same time,” said Dave Sills, NTP’s executive director. “But given the speed of the system and how fast the tornadoes are probably moving, one may have finished just as the other one was starting.”
The first tornado to touch down did so at approximately 11:36 a.m. in London’s Huron Heights area, located in the city’s northeast.
According to the group, maximum wind speeds of 160 km/h were recorded during the twister, which travelled 5.7 kilometres west-southwest and had a maximum path approximately 450 metres wide.
The tornado downed several trees and caused property damage throughout the city’s northeast, including to an apartment complex on Huron Street and other buildings.
“The Huron Heights neighbourhood there … really suffered a lot of tree damage. In some areas, all of the big trees were down,” Sills said.
At London’s airport, a small plane was overturned and damage was reported to several structures.
“Our fire hall, (we) lost several of the main large doors to the fire hall. We had several hangars damaged, losing doors and pieces of roofing,” said Scott McFadzean, CEO of the London International Airport.
“We had a vehicle screening area where we had a trailer and overhead coverage which was completely destroyed, and suffered some other damage to the roof of the terminal building…. All in all, a very difficult situation, but we’ve done a good job, the staff here at the London airport has done a great job cleaning up and recovering.”
A damage estimate was not immediately available. McFadzean says insurance company officials are set to visit the airport on Monday. Despite the damage, there was no impact to service, and the airport’s runways were able to operate immediately after the storm had passed, he said.
The overturned plane, a two-seat Diamond DA20 used for flight training at the Diamond Flight Centre, was tied down at the time of the storm, but was facing into the wind. As a result, the storm lifted the plane into the air, causing the tie-down straps to break, McFadzean said.
“My understanding is that the airplane actually got airborne enough to flip over and land on its back. I don’t have all the details in terms of the condition, but from what I saw, I would expect it to be a complete loss.”
No injuries were reported and the damaged aircraft was taken away a few hours later, he said.
The second confirmed tornado touched down three minutes after the first, at 11:39 a.m., along Green Valley Road in the city’s south end. Researchers say it travelled 3.4 kilometres west-southwest and had maximum wind speeds of 175 km/h and a maximum path width of 400 metres.
A warehouse belonging to Commonwealth Plywood along Green Valley saw significant structural damage to its roof and to an exterior wall as a result of the twister. A large hydro pole was also left leaning, and there were several trees that were downed by the winds, Sills said.
“It wasn’t a really consistent, heavy path of damage all the way along. It really started with that industrial building, taking the roof off and part of the wall. There really wasn’t anything we could see ahead of that,” Sills said of the second tornado.
“After that, it was a few trees here and then a bunch of shipping container kind of things. It was a mix of damage…. As it hit all of these industrial buildings, there was some kind of debris, it was either foam or plastic or a combination of that, that was just all over everything.”
The storm left tens of thousands of Londoners in the dark for hours. While power was restored to most customers by Monday, the utility noted in a tweet that some areas with severe damage were still offline.
Global News reached out to London Hydro’s spokesperson for comment on Friday but did not receive a response by publishing time.
Both tornadoes were embedded along the leading edge of the derecho, buried just behind the intense rain, Sills said, meaning nobody could have seen or gotten a photo of a funnel cloud appearing.
“In fact, no one has photographed a funnel cloud or anything like it anywhere along the derecho, even in Uxbridge, where there was an EF2 tornado,” he said.
“We have to go by just the damage and also radar. We can see that there’s a long, narrow path with these, and that’s the telltale sign of a tornado, but also, there was a bit of rotation over top of each of these (in) the radar from Exeter.”
The two tornadoes are among five that have been confirmed across Canada so far this year, though Sills notes the team is “basically at the tip of the iceberg” when it comes to reviewing the damage reports they’ve received from across the province and in Quebec as a result of Saturday’s storm.
“We’ll be doing surveying of various damage areas and looking at areas via high-resolution satellite for quite some time to try to identify more enhanced areas of damage and whether they’re downbursts or tornadoes,” he said.
“It’s going to be some time before we get to the end of looking at all of these different events and trying to classify and rate all of these. We hope to have a really good picture of the derecho and the damage it caused and the impact it had by the end of our study of this.”
Almost a week removed from the storm, cleanup across the city, and across the province, remains an ongoing task, one that may take several weeks to complete.
In London, city officials say they’ve fielded more than 450 service requests from members of the public about downed trees, broken tree limbs and other tree-related damage.
“The one area that I got to have a look at personally early on was up in Huron Heights…. It was amazing to see the trees uprooted one after another down some of the streets there,” Scott Stafford, director of parks and of forestry with the city, said on Friday.
Informed that a EF1 tornado had touched down in the area, Stafford replied, “certainly makes sense from what I saw there.”
The city says crews continue to assess and address tree damage and have been responding to calls on a priority basis, with blocked roads and trees on buildings and vehicles tended to first. Such emergent matters were dealt with over the course of this week, with crews working 12 to 14 hours a day, Stafford said.
“We’ll just be plugging away at those other things with broken branches and limbs hanging in trees and brush cleanup, stump cleanup. We’ve got road, sidewalk repairs that need to happen. There’s lots of work that’s still happening out there,” he said.
Elsewhere across the province, at least 11 deaths were reported as a result of the storm, which initially developed near Sarnia late Saturday morning and tracked northeast across the province.
The latest death, reported Thursday, was that of a 58-year-old man who provincial police say was struck by a falling tree in a remote area of the Municipality of Marmora & Lake.
Speaking with The Canadian Press, Peter Kimbell of Environment Canada noted that a “vast majority” of damage seen during the storm was the result of the derecho, which he says are rare, with the last significant one occurring in 1999.
The storm was responsible for an EF2 tornado with 195 km/h winds that was confirmed to have touched down in Uxbridge in Durham Region, leaving significant damage in its wake.
Tens of thousands of Ontario residents were still without power on Friday, with some expected to remain offline for several days, according to Hydro One.
— with files from The Canadian Press