Tornado research group confirms tornadoes in East Zorra-Tavistock
By Lee Griffi
An investigation by the Northern Tornadoes Project (NTP) has confirmed two tornadoes and a downburst in the Tavistock area on Sept. 2. No injuries were reported, but there were several reports of property and crop damage along with power outages.
The three extreme weather events occurred as a line of strong storms passed through much of Southern Ontario late in the afternoon. The first tornado formed west of Tavistock and moved into the town, causing tree and house shingle damage. It was rated an EF0 and carved a clear path through crops in the township.
This tornado started at approximately 5:23 p.m. with an estimated maximum wind speed of 125 km/h, a track length of 6.24 kilometres and a path width of about 410 metres.
“A second tornado began north of Tavistock near Shakespeare and tracked toward the southeast. This tornado caused significant damage to agricultural structures and trees, rated at EF1. Its path could also be clearly seen at times in crops,” added a statement on the group’s website.
It started around 5:25 p.m. and had an estimated maximum wind speed of 155 km/h, a track length of 8.29 kilometres and a maximum path width of 420 m. Damage to several farm buildings, including a destroyed barn, along with tree and crop damage, was reported north and east of Tavistock.
The NTP is a research initiative based at Western University in London, dedicated to finding, documenting and studying tornadoes across Canada. It was launched in 2017.
“Finally, both tornadoes converged toward a downburst that developed just east of Tavistock and travelled more than 17 km toward the east-southeast. EF0-rated damage to agricultural structures and trees occurred with this downburst as well,” added the statement.
Trees, farm buildings and the roof of a home were damaged east of Tavistock. The downburst had an estimated maximum wind speed of 125 km/h, with damage found over an area approximately 17.0 kilometres long and up to 7.5 kilometres wide.
A downburst is a powerful column of air that sinks rapidly from a thunderstorm and spreads outward when it reaches the ground, producing very strong, often damaging winds. Think of it as a burst of air that spreads out in all directions when it hits the ground.
The NTP says there is evidence a tornado likely occurred near Bamberg in Wellesley Township during Wednesday’s severe storm, with investigators continuing to assess the damage and determine the tornado’s strength and path.
NTP Director David Sills said the group’s investigations are extremely thorough.
“We watch the storms in real time just to get an idea of where damage might be. We actually produce our own tornado and downburst forecast so our team members know when they may have to fly across the country.”
The next step is to comb social media for damage reports to populate a map which shows where damage has occurred.
“Then we start planning where our teams might head for ground and drone surveys. We go to the areas of worst damage and go out from there. Typically, for a tornado, you’re talking about a long, narrow path of damage.”
Once a tornado is confirmed, it is rated using the Enhanced Fujita, or EF, scale.
“Sometimes we end up doing some forensic analysis if a large tractor or combine was thrown a great distance; then we can do the engineering calculations for that, which helps us with rating. The last part is trying to document how long and how wide the track would be.”
Sills said the NTP has investigated thousands of tornadoes since the project began. He added the organization recently signed an agreement with Environment and Climate Change Canada clarifying the roles and responsibilities of each agency when it comes to severe weather.
“Their space is forecasting and warning and ours is the post-event space. We confirm the events and give the rating. It’s been like that for a while, but the agreement makes it clearer. It was a long time negotiating it, and it certainly helps everyone understand what their roles are.”
Sills explained he spent 20 years at Environment Canada and part of his role was conducting damage surveys, a role which was never given much in the way of resources.
“We did our best, but with the NTP we are spending upwards of $1 million a year doing this, and the results show it. We’ve nearly doubled the tornado count across Canada, and that’s the kind of effort that’s required to do this the right way.”
The University of Western does provide some support for the organization, but because it does not receive any government funding, it is forced to rely mainly on a private donor to perform its duties.
“It’s called ImpactWX out of Toronto. It’s led by someone who is a storm chaser, weather enthusiast and philanthropist. That was the core of the funding that goes into both the NTP and the Canadian Severe Storms Lab at the University of Western,” he explained.
NTP data is used to verify Environment Canada’s tornado warnings through performance assessments, something that has led to improved forecasting of major weather events.
“We also use it for risk analysis and informing the building code. We also look at trends over a longer time frame to see how things are changing. Some regions may see an increase and some a decrease. There are lots of changes going on due to climate change, and that’s what we need to sort out.”
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