There were no injuries reported but the experience was terrifying for residents of small towns, including Cremona, about 65 kilometres northwest of Calgary.
Diana Satchwell had taken a break from cutting grass when she noticed dark clouds approaching and a funnel cloud forming.
"And I just got downstairs when I heard a big bomb, and I thought 'I wonder if all my windows went,'" Satchwell told CBC News. "And it was the roof coming off the house, torn right off and thrown 25 metres away up a hill."
Within hours dozens of neighbours arrived to help start to help Satchwell clear the debris from damaged outbuildings and a battered cattle trailer.
"We have to be thankful no one was hurt," Satchwell said, "but [it's] just one big mess, that's for sure."
Allen Graham, a neighbour, said he saw the tornado touch down.
"It sounds like a diesel train," he said. "It's coming for you — it's just a terrible roar, that's the first thing I noticed. Then I looked up into the sky and I could see her touch."
Lorne Thompson and his wife were cruising toward British Columbia to begin a two-week vacation when a tornado picked up their vehicle.
"It flipped us into the hay field here and I thought we were OK," Thompson recalled. "And then it hit us again and flipped us around and twisted us the other way — facing back north."
Thompson said he and his wife were bruised and shaken in the incident, but otherwise unharmed.
The storm, which also brought a period of heavy rain to Calgary, came on the heels of a storm that dropped baseball-sized hail on Cardston, southwest of Lethbridge on Friday.Suggest a correction