A tropical cyclone is a storm system characterized by a large low-pressure center, a closed low-level circulation and a spiral arrangement of numerous thunderstorms that produce strong winds and heavy rainfall. Tropical cyclones feed on the heat released when moist air rises, resulting in condensation of water vapor contained in the moist air. They are fuelled by a different heat mechanism than other cyclonic windstorms such as nor'easters, European windstorms and polar lows, leading to their classification as "warm core" storm systems. Most tropical cyclones originate in the doldrums near the Equator, approximately 10 degrees away.
The term "tropical" refers to both the geographic origin of these systems, which form almost exclusively in tropical regions of the globe, as well as to their formation in maritime tropical air masses. The term "cyclone" refers to such storms' cyclonic nature, with anticlockwise rotation in the Northern Hemisphere and clockwise rotation in the Southern Hemisphere. Depending on its location and intensity, a tropical cyclone may be referred to by names such as "hurricane", "typhoon", "tropical storm", "cyclonic storm", "tropical depression" or simply "cyclone".
- Pictured: Typhoon Tip