Tornado strikes were 'luck of the draw,' says meteorologist

By Trevor Pritchard, CBC News Ottawa, September 23, 2018

They're more associated with the prairie provinces.

The devastation had Ottawa Mayor Jim Watson drawing comparisons to Oklahoma.

So how did two powerful tornadoes end up devastating parts of Ottawa-Gatineau?

"I think it's been just the luck of a draw. Because tornadoes do happen in Ontario. And September certainly [is] rare to get a tornado," said Gerald Cheng, a meteorologist with Environment Canada.

(...) Hot muggy conditions

On Friday afternoon, temperatures in Ottawa-Gatineau hit 28 C, with the humidity making conditions feel — at their absolute muggiest — closer to 37, according to data from the weather agency.

When we have tornadoes, they are certainly capable of destruction just like this.

- Gerald Cheng

That meant that conditions were "really ripe" for thunderstorms that could produce tornadoes, Cheng said.

https://www.cbc.ca/news/canada/ottawa/environment-canada-gerald-cheng-ottawa-gatineau-tornado-1.4834988