Cyclone

In meteorology, a cyclone is a large air mass that rotates around a strong center of low atmospheric pressure, spinning counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere, with the rotation and pressure gradient held in approximate balance by the Coriolis effect. Cyclone is the broader term: every tropical cyclone is a cyclone, but the category also includes extratropical, subtropical, and polar cyclones. Tropical cyclones are warm-core systems fueled by heat released as water vapor condenses over warm ocean water, while extratropical cyclones are cold-core systems that form along temperature gradients in the mid-latitudes. Cyclones develop through cyclogenesis, with extratropical systems typically lasting two to six days as they are steered by the jet stream, while tropical systems form over warm water and weaken once they move over land.