An atmospheric m. circulation (low-pressure system) with rotating and converging winds, in which the center has a relative pressure minimum. It usually has a diameter of 2000 to 3000 kilometers. When developing, a cyclone typically consists of a warm front pushing northward and a cold front pushing southward with the center of low pressure (cyclone center) located at the junction of the two fronts. Cyclones in the Northern Hemisphere rotate counter-clockwise while Southern Hemisphere cyclones rotate clockwise.

This definition is in context to Hurricane. See more contextual defintions for Cyclone.