(Update) Tornado passes through Ontario town as storms cause widespread flooding, damage

A tornado left a trail of damage in a southwestern Ontario community on Saturday as a major storm system drenched much of the southern part of the province with heavy rain and caused localized flooding.

David Sills, executive director of the Northern Tornadoes Project at Western University, confirmed a tornado touched down in the community of Ayr, Ont., around 11 a.m. on Saturday.

The team has been in the area since the afternoon and is currently assessing the width, length, extent of damage and other data, he said.

To identify whether a tornado has made a touchdown, Sills said researchers tend to look at the path of damage. He said this tornado left a long but narrow path behind it, with no damage beyond its boundaries.

"We rate the tornadoes based on the damage they've caused," Sills said.

"We've got trees down in every direction possible. … This one was on the weak side."

The weather conditions in play across the province on Saturday, which included heat, high humidity, variable winds and a low-pressure system, can set the stage for tornado activity, said Environment Canada meteorologist Trudy Kidd.

The storm had passed by late afternoon, but left behind a trail of downed trees and power lines, said Sue Foxton, mayor of North Dumfries, the township that includes Ayr.

It also tore portions of walls and roofs off local buildings, she added. 

"We got the wind, but not as much rain," she said, noting damage was severe in some areas.

A news release from the Township of North Dumfries said the local sports park was among the damaged sites in town. 

There was a power outage because of extensive damage to the infrastructure caused by downed trees, it said.

"It is anticipated that the power outage in and immediately adjacent the high impact zone will be out for an extended time period," the release reads.

Environment Canada had special weather statements in effect late Saturday across southern Ontario, as well as rainfall warnings for several areas including Toronto and Mississauga.

The agency said regions under severe thunderstorm watch could see wind gusts of up to 90 km/h, up to 50 millimetres of rain and nickel-sized hail. It also said the thunderstorms were expected to dissipate in the evening. 

A special weather statement in place for many southern Ontario communities said significant rainfall was expected until the end of the weekend, with total rainfall of up to 80 mm expected through Sunday.

"This weather pattern typically brings rapidly changing conditions between sunny skies and heavy downpours," the agency said. "Rainfall warnings may be required and issued on short notice to reflect rapidly changing conditions."

Woodbine Entertainment issued a post on X, the social media platform formerly known as Twitter, saying it cancelled the rest of Saturday's scheduled live races, including the King's Plate, due to unsafe racing conditions from the heavy rain. 

Heavy rain has caused localized flooding in areas across Mississauga, Ont., according to a news release from the city, with all local creeks and rivers either at capacity or flooding into parks and green spaces. 

The weather has also caused traffic disruptions, dangerous road conditions and closures, the release said, adding a heavy rainfall warning remains in effect for the city throughout the weekend. 

The storm caused flight diversions and ground delays at Toronto Pearson Airport, its operator said on X, adding it's having a major impact on passengers. 

The rain has also resulted in various leaks in Terminals 1 and 3, though both were still operational, the Greater Toronto Airports Authority said on X. The Terminal Link Train experienced a service disruption in the late afternoon due to water leaking on a platform, but later returned to normal service, it added. 

The Toronto and Region Conservation Authority issued a flood watch through the end of Sunday, saying all shorelines, rivers and streams within the Greater Toronto Area should be considered dangerous due to higher and rapidly changing water levels and unstable river banks. 

This report by The Canadian Press was first published Aug. 17, 2024.

This is a corrected story. A previous version named Sue Foxton as the Mayor of Ayr. She is, in fact, mayor of North Dumfries Township, which includes Ayr.