Storm damage reported in the Uxbridge and southern Ottawa area - May 22/22 (Photo via Northern Tornadoes Project on Twitter)Storm damage reported in the Uxbridge and southern Ottawa area - May 22/22 (Photo via Northern Tornadoes Project on Twitter)

Northern Tornadoes Project investigating storm as death toll climbs to 10

At least 10 fatalities have now been linked to a widespread long-lived windstorm that developed in a line of thunderstorms near Sarnia late Saturday morning.

Environment Canada Warning Preparedness Meteorologist Peter Kimbell said the origin of the thunderstorm line began in the state of Illinois at around 5 a.m. and reached Sarnia-Lambton around 10:45 a.m.

"Thunderstorms are all about updrafts and downdrafts," said Kimbell. "When the downdrafts take hold, they can sometimes orient themselves in lines. If it persists long enough it can cover over 500 kilometres or so and include wind speeds of 110 or 115 kilometres an hour, we call that a derecho and they're pretty rare."

So rare, Kimbell said Ontario hasn't experienced a storm like it in many years.

"The last time Ontario experienced an event like this was probably in 1999, so more than 20 years ago. It didn't affect southern Ontario but was more northwestern Ontario, down through central Ontario and into eastern Ontario."

Saturday's storm, which tracked northeastward over southern Ontario reaching Ottawa Saturday afternoon, resulted in extensive damage to trees, buildings and power lines.

More than 10,000 customers lost electricity, some of which had yet to see their service restored by Tuesday morning.

The Northern Tornadoes Project, a partnership between Western University and Impact WX, is assessing the damage and trying to determine if tornadoes were embedded in the derecho.

"We do know that sometimes along a squall line, we'll get a couple of spin ups that may actually produce tornadoes. Personally, I'm not convinced that there were any," Kimbell said. "I think that the downburst straight line winds were so strong that they probably would have overpowered anything else, but I can't be sure. It is possible that they may discover that there were one or two tornadoes along this path, but without doubt the vast majority, perhaps almost all of the damage, was caused by straight line winds."

Wind gusts peaked at 132 kilometres an hour at the Kitchener-Waterloo Airport and 120 kilometres an hour at Toronto Pearson International Airport and Ottawa International Airport.

Environment Canada is asking anyone with photos and videos of the storm to send them to Environment and Climate Change Canada at ONSTORM@EC.GC.CA or post them on Twitter with the Hashtag #ONSTORM.

Read More Local Stories