How did such a severe hailstorm come to develop last week in Calgary, Alberta?
Margaret Robertson Chicago
A severe thunderstorm hit the Calgary area last week, dropping massive amounts of hail, some stones as large as tennis balls. The hail, driven by high winds, stripped trees of leaves, smashed windows and windshields, shredded siding and in many areas covered the ground to a depth of two feet. Torrential rains, flooded the city swamping numerous cars. Damage estimates from the massive storm are forecast to top one billion dollars. The storm, which began shortly before 7 pm on Saturday June 20, produced several funnel clouds and at least one tornado southeast of the city. The tornadic supercell developed along a frontal boundary draped across the area, with brought together similar conditions that produce severe thunderstorms in the Great Plains of the U.S.