By Andrew Duffy, Ottawa Citizen, June 3, 2019
That Ottawa has been struck by three tornadoes in the past nine months defies statistical probability, Environment Canada says.
Ontario has averaged 12 to 13 tornadoes each year for the past three decades, with most of those touching down in “tornado alley,” a corridor of land between Windsor and Barrie.
“If most occur in Southern Ontario, then maybe one or two occur in Eastern Ontario,” said Peter Kimbell, a warning preparedness meteorologist with the Meteorological Service of Canada, a division of Environment and Climate Change Canada.
“So to have two in Ottawa last year and one this year is a statistical anomaly. It’s just so unlikely to happen. It’s like rolling sixes three times in a row. It’s a freak incident.”
https://ottawacitizen.com/news/local-news/third-ottawa-tornado-inside-year-a-statistical-anomaly-environment-canada