Blizzards
A blizzard is a severe snowstorm characterized by strong winds. By definition, the difference between blizzard and a snowstorm is the strength of the wind. To be a blizzard, a snow storm must have winds in excess of 56 km/h (35 mph) with blowing or drifting snow which reduces visibility to 400 meters or ¼ mile or less and must last for a prolonged period of time - typically three hours or more. Ground blizzards require high winds to stir up already fallen snow.