Tropical Cyclone

A tropical cyclone is a warm-core, low-pressure system that forms over warm tropical oceans and draws its energy from latent heat released as moist air condenses. Formation requires sea surface temperatures of at least about 26.5 degrees Celsius through a deep mixed layer, weak vertical wind shear, sufficient mid-tropospheric humidity, a pre-existing disturbance, and a Coriolis force large enough to spin up rotation, so genesis avoids the band within about 5 degrees of the equator. The mature storm has a calm eye ringed by an eyewall of the strongest winds. Called a hurricane in the Atlantic and eastern Pacific and a typhoon in the western Pacific.