But what, exactly, is a blizzard? A blizzard doesn't always mean "a lot of snow," though it can certainly bring heavy snowfalls, as this storm is expected to along parts of the East Coast. Rather, the National Weather Service defines it as a snowstorm with winds regularly above 35 miles per hour and "considerable falling" or blowing snow for at least three hours.
Residents should prepare for the worst of the storm late Sunday night, when snowfall rates could exceed 2 inches per hour. The weather service believes the heaviest snow will come down from 7 p.m. Sunday through about 12 p.m. Monday. The snow is expected to develop Sunday morning and afternoon, possibly mixing with rain at the onset before tapering off late Monday morning into Monday afternoon.
Right now, forecast models are split. Some keep the storm far enough out to sea to spare New York City from snowfall but others show snow reaching coastal New Jersey and Long Island late Saturday into Sunday. A shift of just 50 to 100 miles in either direction could change everything, from rain versus snow to whether the city sees accumulation at all.