Officials with Western University’s Northern Tornadoes Project (NTP) have confirmed that severe weather which passed through the London area Tuesday afternoon produced a preliminary EF0 tornado.
The tornado touched down briefly near London International Airport just after 2:30 p.m. It’s the first confirmed twister in London and Middlesex County this year, according to NTP data.
Surveyors with NTP attended the scene on Tuesday but initially located no damage, however, a subsequent visit on Wednesday morning turned up weak tree damage, said research assistant Francis Lavigne-Theriault.
“So far the damage we’ve found was just a few trees outside of the airport. There was no damage there by the airport or any planes or anything like that,” Lavigne-Theriault said.
Based on the evidence observed, including a snapped tree, investigators have determined that Tuesday’s tornado had a maximum wind speed of 115 km/h, placing it in EF0 territory on the Enhanced Fujita scale.
According to Environment Canada, tornadoes that see wind speeds of 90 to 130 km/h are considered EF0. The most severe rating on the EF-scale, an EF5, is where there are wind speeds of 315 km/h or more.
“It was definitely not super expected, but it is this time of year where you see tornadoes a lot. So it’s something that I think people are mostly used to now,” Lavigne-Theriault said.
NTP is still surveying the scene to determine the path and length of the tornado’s trail, if it exists, he added.
Due to the tornado’s proximity to the airport, researchers aren’t able to fly a drone over the scene to get an aerial perspective, meaning the investigation will have to rely on ground-level surveys and satellite imagery.
“We’re going to … look at satellite (images) to see (if) maybe there’s other damage that we missed from the ground survey. We’re hoping to release that in the next few days, if not next week.”
No tornado warning was issued by Environment Canada on Tuesday afternoon.
The tornado came hours after the agency issued a special weather statement for the region calling for afternoon showers and thunderstorms.
The special weather statement was later dropped, and a heat warning was issued for most of southern Ontario.
That advisory remained in place as of early Wednesday afternoon, warning of several days of heat and humidity with afternoon humidex values of near 40 C until the end of the workweek.
The purpose of the NTP, launched in 2016 and expanded in fall 2019, is to report and catalogue every tornado that touches down in Canada.
The project utilizes planes, drones and high-resolution aerial and satellite imagery to find tornadoes in more remote areas that would otherwise go unreported.