Storms, Extreme Weather, and Precipitation

Tropical cyclones are intense, rotating storm systems that form over warm ocean waters, generally requiring sea surface temperatures above roughly 26.5°C to supply the heat and moisture that fuel their convection, along with sufficient Coriolis force to organize rotation, which is why they almost never form within about 5 degrees of the equator. A mature tropical cyclone develops a warm core with a calm central eye surrounded by an eyewall of the most intense winds and rain, itself encircled by spiraling rainbands. The same phenomenon carries different regional names depending on where it forms: hurricane in the Atlantic and northeastern Pacific, typhoon in the northwestern Pacific, and cyclone in the South Pacific and Indian Ocean. Intensity in the Atlantic and eastern Pacific is commonly measured on the five-category Saffir-Simpson scale, based on sustained wind speed.