The term used for cyclones that originate over tropical waters. It is a warm core low pressure system which is non-frontal and has organized circulation. Depending on sustained surface winds, the system is classified as a tropical disturbance, tropical depression, tropical storm, or a hurricane or typhoon.
An intense low pressure system which forms over warm ocean waters at low latitudes. The typical structure consists of bands of cumulonimbus clouds which spiral towards a clear central eye, though this can be obscured by high cirrus cloud. Tropical cyclones are associated with extremely strong winds, torrential rain, storm surges (in coastal areas) and huge seas. The name Tropical Cyclone is usually used for systems in the southwest Pacific and Indian Oceans, while other names such as tropical storms, hurricanes and typhoons are used in other parts of the world. If they attain maximum mean winds above 117 km/h (63 knots) they are called Severe Tropical Cyclones (Category 3 or above).
a large storm rotating around an area of very low pressure, with strong winds blowing around the centre