A revolving tropical storm in which the winds circulate around a low-pressure centre, the whole system moving linearly at the same time. This type of storm goes under different names in different parts of the world, ‘typhoon’ and ‘hurricane’ being the most familiar. A full-scale cyclone is rare in Northern European waters, but the type of weather system which centres around a low-pressure area is called Cyclonic, and that is extremely common in these areas. In the northern hemisphere cyclonic winds run anti-clockwise in a cyclonic system (generally bad weather) and clockwise for an anti-cyclone (good weather). In the southern hemisphere these directions of rotation are reversed.