Tropical cyclone

A tropical cyclone is a circular air movement that starts over the warm ocean waters in the warm part of Earth near the Equator. Most tropical cyclones create fast winds and heavy rain. While some tropical cyclones stay out in the sea, others pass over land. They can be dangerous because of flooding and because the winds pick up objects, including things as big as small boats. Tropical cyclones can throw these things at high speeds.

Tropical cyclones, hurricanes or typhoons form when convection causes warm, moist air above the ocean to rise. They begin as a group of storms when the water gets as hot as 80 °F (27 °C) or hotter. The Coriolis effect made by the Earth's rotation causes the winds to rotate. Warm air rises quickly. Tropical cyclones usually move westward in the tropics, and can later move north or south into the temperate zone. The "eye of the storm" is the center. It has little rain or wind. The eye wall has the heaviest rain and the fastest winds. It is surrounded by rain bands which also have fast winds.

Tropical cyclones are powered by warm, humid ocean air. When they go onto land, they weaken. They die when they spend a long time over land or cool ocean water.