Researchers use crowdsourced data to confirm recent tornado

A research group confirmed a powerful storm that ripped through north Wellington County last week included a tornado touchdown. 

The Northern Tornado Project (NTP), a Western University research group aimed at better understanding and detecting tornadoes, said on Twitter an EF1 tornado with speeds up to 160 km/hr touched down after 5 p.m. on Sept. 7 outside of Harriston and made its way through Kenilworth, just south of Mount Forest. 

A tornado isn't always immediately confirmed, in this case it was days later. 

David Sills, NTP executive director, said in a phone interview the initial focus was on the damage from an initial tornado closer to Lake Huron. 

According to their data, the storm dissipated past the Lucknow area but they noted on radar it re-intensified as it approached Harriston, developing a rotation.

Sills said determining a tornado is a combination of satellite or radar imaging along with crowdsourced damage reports that determines where they send a team to investigate if there truly was a tornado.

“Based on all those things we start to get an idea where the rotation was with the storm and where the damage occurred and then we can say ‘okay well this is possibly a tornado here,’ and send out our ground survey team,” Sills said. 

He said remote sensing has allowed NTP to track tornadoes in very remote areas with either no-population or with a population that doesn’t typically use social media, such as the large Mennonite community that exists in the area of this tornado. 

However, Sills said sometimes satellite imagery can take more than a week to get and damage gets cleaned up quickly so understanding where to send a team is crucial.

This is where damage reports from the public come into play.

Bailey Allard, a north Wellington County storm chaser, was not able to track this particular storm due to work.

Later, she surveyed the damage and noted around Farewell, a hamlet south of Mount Forest, the trees weren’t hobbled over but the tops were twisted off and the limbs were missing which is “a very strong indication of rotating winds and tornado damage.”

This information was passed along to the NTP. 

“It helps them to get out there faster so that they’re able to assess the damage and classify it as what strength and collect their own data,” Allard said. 

Retired OPP officer Kirk MacDonald also storm watches as he said he’s been fascinated by extreme weather since he was a child. He notes storm watchers range in experience and background from meteorologists, spotters to just members of the public posting photos and videos to help track extreme weather. 

“They need people on the ground at times to confirm what is actually going on,” MacDonald said. 

However, MacDonald stressed the public shouldn’t go chasing storms without proper training. 

“If you don’t have a good knowledge of meteorology or how storms and weather can change, you could be putting yourself into danger and not being help to anybody,” MacDonald said. 

“It can be extremely dangerous, not just for themselves but other members of the public.”

Using the data gathered, the NTP have determined the preliminary track going from south of Harriston to Kenilworth but Sills said they’ve been getting further additional damage reports that may indicate a further track. 

Sills said getting more of this kind of data has many practical uses, for example municipalities to know the tornado risk to plan infrastructure and emergency preparedness. 

More tornadoes are being reported each year but Sills said this can’t necessarily be attributed to climate change as they may just be getting better at finding them. 

As much as fascination plays a factor, MacDonald said the most important reason for tracking storms is for public safety because patterns can be noted for tornado watches or warnings. 

Allard noted the conditions on Tuesday are very similar to a week. 

“We are starting to see things that are repetitive, so we’re not sure if it’s because we have more observations, more people are paying attention but right now for this particular event, it does seem that we have a lot more notification and we’re able to alert the public well in advance,” Allard said.