Currently, parts of Maryland, Washington, D.C., and Northern Virginia are under a blizzard warning ahead of the snowstorm expected to hit Friday evening. New York City and southern New York state are under a blizzard watch along with parts of New Jersey, Maryland and southeastern Pennsylvania. Parts of central Pennsylvania, Virginia, North Carolina, South Carolina, West Virginia, Kentucky, Tennessee and Georgia are under a winter storm warning. Blizzards are defined by the National Weather Service as a storm with large amounts of snow or blowing snow, winds of 35 mph or stronger, and visibility of less than a quarter of a mile for at least three hours. A blizzard warning is issued when these conditions are expected. A winter storm warning is issued when one or two of these conditions are expected, according to AccuWeather.