n.
Any large system of winds that circulates about a centre of low atmospheric pressure in a counterclockwise direction north of the Equator and in a clockwise direction south of it.
Cyclones that occur in the mid-and high latitudes are known as extratropical cyclones; they are frequently preceded by thickening and lowering clouds, followed by precipitation. Cyclones that form in the lower latitudes are known as tropical cyclones; smaller than extratropical cyclones, they tend to be more violent and can cause considerable damage (see tropical cyclone ). Wind systems that circulate around a high-pressure centre in directions opposite to that of cyclones are known as anticyclones.