What is a blizzard and how is it formed?

A blizzard requires three things to form: temperatures below freezing at ground level and in the clouds to allow snow to form, enough moisture to allow clouds and eventually snow to form, and a mass of warm air rising over a mass of cold air that creates strong winds. read more

The first prerequisite for a blizzard is snowfall. When the jet stream dips to the south, it can carry warm, moisture-laden air northward, where it encounters the cold, dry air that can trigger a winter storm. A significant amount of snow is required for a blizzard, but the snow does not have to fall during the storm. read more