Cyclone

A large-scale circulation of winds around a central region of low atmospheric pressure, counterclockwise in the northern hemisphere, clockwise in the southern hemisphere.

Cyclone (depression, low, low-pressure area) Area in the atmosphere in which the pressures are lower than those of the surrounding region at the same level. It is represented on a synoptic chart by a system of isobars at a specified altitude level (or a system of contours at a specified pressure level) which enclose relatively low values of pressure (or altitude). In its development a cyclone usually has the following phases. A wave (young) cyclone forms and moves along a front. Mature cyclone has well-developed warm sectors and both cold and warm fronts. Occluded cyclone is that within which there has developed an occluded front.

(abbrev. CYC) - A large-scale circulation of winds around a central region of low atmospheric pressure, counterclockwise in the Northern Hemisphere, clockwise in the Southern Hemisphere.

An atmospheric closed circulation rotating counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.