A blizzard (or winter hurricane)'s a severe winter storm condition characterized by low temperatures, strong winds, and heavy blowing snow. Blizzards are formed when a high pressure system, also known as a ridge, interacts with a low pressure system; this results in the advection of air from the high pressure zone into the low pressure area. Geography Definition According to Environment Canada, a winter storm must've winds of 40 km/h (25 mph) or more, have snow or blowing snow, visibility less… (More on Blizzards)