Twenty years has passed since a F3 tornado swept through Pine Lake's Green Acres campground in Alberta, which killed a dozen people and "turned trailers into kindling" on July 14, 2000. It struck the campsite at approximately 7 p.m. This was the first deadly tornado in Canada since 1987, when an F4 tornado killed 27 people in Edmonton Alberta and injured 300+. This specific tornado had formed out of a severe thunderstorm which had formed on the eastern slopes of the Canadian Rockies and then moved rapidly eastward, encountering a narrow band of low-level moisture that caused it to develop into a supercell thunderstorm. It touched down about 5 km (3.1 mi) west of the campground and was on the ground for approximately 20 km (12 mi).
The twister's damage occurred in a swath 800 to 1,500 metres wide. The winds within the central corridor reached 300 kilometres per hour with hail that was said to be as large as baseballs.
About 140 people required various levels of medical attention due to injuries, while another 1,000 people were displaced by the tornado. 'Miracle baby' Ashley Thomson was just four months old when she was ripped from her car seat and sucked up as high as a three-storey building. The twister then set her down, completely naked, a few hundred metres away on a golf driving range. She was left with little more than a cut to her left foot,"according to the article by CBC.ca See video accounts of the story here, via CBC.ca
On average, there are around 80 confirmed and unconfirmed tornadoes that touch down in Canada each year, with most occurring in the southern Canadian Prairies, Southern Ontario and southern Quebec.
Approximately 40 twisters habitually touch down across the Prairies between the months of June and August.
Saskatchewan has the highest per province with about 18 tornadoes, followed by Alberta with an average of 15 tornadoes then Ontario with an average of 12-13 tornadoes each year. Quebec normally has between 4–10.
All other provinces and territories have significantly less threat from tornadoes.
Fewer than 5% of tornadoes in Canada are rated F3 or higher in intensity, where wind speeds are in excess of 225 km/h (140 mph).
In 1912, on June 30th - Canada's deadliest twister hit Regina, Saskatchewan. Known as the Regina Cyclone, was an F4 tornado that devastated the city. More than 300 people were injured and 28 people killed. The total cost of damage was estimated to be around $4.5 million ( which would be an estimated nearly $117M today).
For a variety of reasons, such as Canada's lower population density and generally stronger housing construction due to the colder climate, Canadian tornadoes have historically caused fewer fatalities than tornadoes in the United States.
To learn more about Canadian Tornadoes follow this link.