Three microbursts confirmed near Petrolia, Wallaceburg

An investigation by the Northern Tornadoes Project (NTP) has confirmed a total of three microbursts occurred during a storm that rolled through parts of Petrolia and Wallaceburg last Friday.

NTP, a project founded at Western University that studies tornado events across the country, attended several sites in southwestern Ontario over the weekend that sustained significant damage following a line of severe thunderstorms that travelled across some of the region on July 14.

As a result, the survey team determined three microbursts occurred in areas including Oil City, Whitebread, and Wallaceburg.

Damage from a microburst in Oil City. July 2023. Image via Northern Tornadoes Project.

“In each case, the damaging winds were focused over an area several kilometres in diameter and occurred with heavy rain and hail,” read a blog post by NTP. “All damage indicators suggested winds from between west and north, while the motion of the storms was from the northwest and toward the southeast.”

A microburst, similar to a downburst, is a sudden downward burst of wind that occurs from the base of a thunderstorm across a small area. The air often rushes towards the ground at high speeds before it hits the surface and spreads out in all directions. Microbursts are often responsible for causing extensive tree or building damage.

Of the three microbursts in southwestern Ontario on Friday, damage was first reported at around 5:15 p.m. Friday in Oil City. Surveyors classified damage from that event as an EF0 on the Enhanced Fujita Scale.

“Damage to a large machine shed and tree damage was reported in the Oil City area after a storm passed through,” the report by NTP detailed.

Wind gusts are believed to have reached approximately 125 kilometres per hour.

The next microburst is believed to have taken place at 6:30 p.m. in Whitebread, northwest of Wallaceburg. Surveyors pegged the damage as an EF1.

“Several snapped power poles were reported near Whitebread after a storm passed through the area,” the report by NTP detailed.

Wind speeds from the event in Whitebread are estimated to have potentially reached 145 km/h.

The third microburst in Wallaceburg is suspected to have happened at 6:45 p.m. Damage was also rated as an EF0. Damage from that event was localized to some trees in the area, along with minor roof damage to a retail building. Wind speeds are estimated to have reached 125 km/h.

NTP said no injuries have been reported.

Investigators conducted ground and drone surveys at each location to review damages.

Drone view of two of the 10 power poles that were replaced near Whitebread, with pieces of the original poles still there. The tree just west of the house had a number of large branches broken off. The wheat to the south can be seen to be down from the north (as were the power poles). Image via Northern Tornadoes Project.

Despite a number of trees in Wallaceburg being snapped and uprooted (a good portion with rot), the highest-rated damage was actually to the roof of a small retail building. Image via Northern Tornadoes Project.