Twelve people were killed and more than 100 injured when the Pine Lake tornado hit the Green Acres campground 19 years ago on July 14, 2000.
It was the deadliest Alberta tornado since 1987, when a more powerful twister killed 27 people and injured more than 300 in Edmonton.
While the area east of the Rocky Mountain foothills has been called Alberta’s tornado alley, a study by severe weather scientist David Sills from 1980 to 2009 found Canada’s actual tornado alley is more widespread.
It covers the southern swath of the Prairie provinces and southern Ontario, even overlapping into a portion of Quebec.
Alberta averages 15.4 reported tornadoes a year — which is slightly less than Saskatchewan’s 18, but more than Ontario (12.5), Manitoba (9.6) and Quebec (4.7).
According to information from The Weather Network, the most violent columns of rotating air form from supercells during thunderstorms. And this activity mostly happens during July, generally between 1 and 8 p.m.
Canada ranks second for the largest number of tornadoes in the world, following the U.S., which starts the severe storm season earlier, during the spring.
When turbulent air masses move north during Canadian summers, this country gets about 62 verified tornadoes a year.
Twisters form when moist, high, cold air hits rising hot air, but very few of them touch down to the ground — which is fortunate, as large tornadoes can generate wind speeds of more than 300 miles an hour and can rip buildings off their foundations
More commonly, tornadoes have winds of less than 110 miles per hour and travel only a few miles before the dissipate. Alberta is so sparsely populated that very few of them damage more than some crops or farm sheds.