You probably think of a blizzard as a big snowstorm that makes travel difficult and unsafe. Maybe you’ll even get a snow day because of a blizzard in the forecast. However, it doesn’t even have to be snowing for a blizzard to occur.
A blizzard has more to do with wind than snow. A blizzard occurs when high winds create blowing snow, causing low visibility. Blizzards often occur when snow is falling, but sometimes blizzards or blizzard-like conditions develop when high winds blow previously fallen snow. This is referred to as a ground blizzard. For a blizzard to occur, winds must gust at speeds of at least 35 miles per hours, reducing visibility to a quarter mile or less, for at least three hours.