Where the cold air and warm water meet, a low pressure system forms. The low pressure system causes clouds to form and a storm to develop. A nor'easter forms when cold air often originating in Canada blows over the warm Atlantic Ocean off the coast of the eastern United States.

How is a Noreaster formed?

Nor'easter storms form when cold air meets warm water, creating a low pressure system. That low pressure system forms clouds, which ultimately turn into one of the harsh storms known as nor'easters.

When did the term nor Easter start?

Early recorded uses of the contraction nor (for north) in combinations such as nor'-east and nor-nor-west, as reported by the Oxford English Dictionary, date to the late 16th century, as in John Davis's 1594 The Seaman's Secrets: "Noreast by North raiseth a degree in sayling 24 leagues."