Last week's storm in northern Ont. being investigated for tornado activity

The owner of a northern Ontario campground continues the cleanup after a powerful storm swept through the region last Thursday prompting severe weather and tornado warnings.

The owner of a northern Ontario campground continues the cleanup after a powerful storm swept through the region last Thursday prompting severe weather and tornado warnings.

Trevor Graydon of Mowat Landing Cottages on the Montreal River in New Liskeard captured a video of the intense rain, hail and wind that pummelled his property, taking out his dock and knocking down several tall trees.

Experts with the Northern Tornadoes Project out of Western University said the damage appears to have been caused by a downburst.

"With a tornado, we've got air that's coming into the bottom of the storm and then up … with a downburst, you've got air that's starting in the storm and then falling out and spreading out. So it's down and out rather than in and up," David Sills, executive director of Northern Tornadoes Project, told CTVNewsNorthernOntario.ca in a video interview.

"With the video that you sent, all of the highest winds occurred while there was heavy rain and hail and it was kind of a longer event, several minutes. That's typical of downbursts because they usually go for three, four, five maybe even longer minutes and they're accompanied by heavy precipitation, including hail, so that the worst winds will come when it is just like a whiteout outside."

Sills said tornadoes typically follow precipitation, rather than occurring at the same time, and dust and debris will be seen swirling around for just under a minute.