Ontario’s First Confirmed Tornado of 2025: EF0 Touches Down Near Woodstock Last Week

/

NOTE: YOU CAN CLICK ON THE MAP TO OPEN A ZOOMABLE IMAGE

Ontario’s tornado season has officially begun. The first confirmed tornado of 2025 touched down during the early morning hours of May 16th, just south of Lakeside, Ontario, northwest of Woodstock.

The tornado developed along the leading edge of a line of storms that had tracked into the province from Michigan.

While this EF0 tornado near Lakeside was the first confirmed in Ontario this year, it wasn’t the first in Canada.

According to the Northern Tornadoes Project, this brings Canada’s confirmed tornado count for 2025 to five.

The season began with an EF0 tornado in Alberta in early April, followed by an EF1 in Quebec later that month. Just one day before the Lakeside event, two EF0 tornadoes were confirmed in Manitoba on May 15th.

With peak season still ahead, this serves as a timely reminder that severe weather can happen quickly and under conditions that don’t always look extreme on the surface.

Even low-end risks deserve attention, especially when storms arrive at night, when people are less likely to be tuned in.

The Tornado: A Narrow but Confirmed Touchdown Near Lakeside

Survey map for the Lakeside EF0 tornado (source: Northern Tornadoes Project)

According to the Northern Tornadoes Project (NTP), the tornado developed just south of the village of Lakeside, approximately 25 km northwest of Woodstock. It touched down around 3:00 AM EDT, shortly after a squall line of thunderstorms entered the region from the west.

Drone photo of worst damage point featuring multiple snapped conifers (source: Northern Tornadoes Project)

Damage was limited to trees and a power pole, with no injuries reported. The tornado was assessed as an EF0, with estimated maximum wind speeds of 115 km/h. It travelled a distance of 3.6 km, with a maximum path width of 160 metres, moving generally from the west-southwest (255°).

Radar data shows possible rotation near lakeside (source: iw pro)

Radar imagery at the time showed a compact area of low-level rotation, but due to the storm’s embedded structure and the overnight timing, the event went unwitnessed until damage was reported later that day.

The NTP conducted both ground and drone surveys on May 20th to confirm the tornado’s track and intensity.

This information is sourced from the Northern Tornadoes Project’s full report, which can be found here.

Survey map showing the location of the EF0 downburst (black oval) and collected data (source: Northern Tornadoes Project)

In addition to the confirmed tornado near Lakeside, the Northern Tornadoes Project also verified a separate EF0 downburst near Chatham from the same storm system.

The downburst occurred around 2:15 AM EDT, roughly 45 minutes before the tornado, and caused significant damage to several barns, farm buildings, power poles, and trees.

While similar wind damage was reported across parts of Southwestern Ontario—from Windsor to Shrewsbury—only the enhanced damage south of Chatham was surveyed.

Wind speeds were estimated to have peaked at 130 km/h, placing the event at the high end of the EF0 scale. No injuries were reported.

Timeline: Forecast Leading Up to the Tornado

Forecast models began flagging the potential for severe storms several days in advance, particularly in Deep Southwestern Ontario, where the environment appeared favourable for severe weather.

Instant Weather and the U.S. Storm Prediction Center both noted the possibility of tornadoes — albeit marginal — due to the timing and nocturnal nature of the storms. This provided over 24 hours of advance notice about the potential for severe weather.

Despite the lower-end risk, one storm managed to spin up a brief EF0 tornado shortly after 3:00 AM on May 16th.

Instant Weather first highlighted the tornado potential on Wednesday afternoon, referencing the Storm Prediction Center’s forecast and the setup in Michigan and Southwestern Ontario:

The following morning, just under 24 hours before the confirmed tornado, Instant Weather once again flagged the risk.

This time, the post specifically mentioned that a 2% tornado risk extended into Sarnia, Chatham, Grand Bend, and as far northeast as London, placing the affected area firmly within the broader risk zone:

Later Thursday afternoon, a forecast was issued by Instant Weather calling for the potential of isolated tornadoes overnight. The forecast map outlined a marginal risk that included the area near Lakeside, where the tornado would eventually touch down:

Around 1:47 AM, just over an hour before the tornado touched down, Instant Weather sent out a custom notification for the London area, referencing minor rotation and clearly stating that “an isolated tornado cannot be ruled out”:

At 2:55 AM, Environment Canada issued a Severe Thunderstorm Warning, which included a note that severe thunderstorms can produce tornadoes. This came approximately five minutes before the tornado would touch down near Lakeside

Finally, live coverage was underway on Instant Weather’s YouTube channel during the time the tornado developed around 3:00 AM, as the storm moved through Oxford County.