Northern Tornadoes Project investigating recent storm damage in Tweed, Ont.

The Northern Tornado Project says it will be looking into damage in the Tweed, Ont. area following a storm Monday.

A line of powerful thunderstorms moved across eastern Ontario Monday, prompting several weather warnings, including brief tornado warnings. In Ottawa, two men were critically injured after being struck by lightning on a golf course in the west end.

Executive director of the Northern Tornadoes Project (NTP) David Sills tells Newstalk 580 CFRA's Ottawa Now with Kristy Cameron, a survey team has found a path of damage.

"It's mostly trees, though some of the trees have fallen down on cottages and homes and on hydro lines, causing problems there, but at the moment we can't tell if it's a tornado or a downburst," he said.

The difference between a tornado and a downburst lies in the direction of the wind, he says.

With a tornado you've got winds near the surface going up into the storm and with a downburst you've got air that's coming out of the thunderstorm and spreading out near the surface," he explained. "With a tornado, we're looking at a long, narrow path of damage, whereas with a downburst it's usually a wider area of damage and usually all of the trees are down in the same direction."

Sills says a drone is in the air getting a view of the storm damage for analysis.

The area about 40 km north of Belleville was struck by an EF2 tornado in July 2022. Maximum wind speeds of up to 190 km/h were recorded. The NTP said it was on the ground for more than 45 minutes, and carved a 56-kilometre path of destruction, affecting Rockdale through Actinolite, north of Marmora, Madoc and Tweed. It came just two months after the derecho that tore across eastern Ontario.

Sills said the damage from Monday's storm was not as severe.

"This is going to be on the lighter end. It's looking like it might be EF0; quite a bit less significant and less high-impact than that big tornado last year," he said.

July is typically the peak for tornadoes in Canada, he said. Earlier this week, the NTP reported an EF0 tornado in Stayner, Ont., near Barrie, and there have been reports of tornadoes in Manitoba recently as well.

"We are ramping up, almost July now, so we'll get into the peak of the year in the next few weeks," he explained. "Once all the summer heat arrives up in Canada from the U.S. then we're right in the middle of storm season here. It'll start to taper off in August and then really drop off in the fall."