Hurricanes are one of the most intense and destructive weather phenomena on Earth. They can cause devastating damage to homes, businesses, and natural resources, as well as loss of life. NOAA works to understand these storms in order to better predict their strength, track them as they develop and strike, and help people prepare for them.
A hurricane is a large, rotating weather system with a low pressure center and organized convection (i.e., thunderstorm activity). Its central area, called the eye, is clear and usually cloud-free. The surrounding cloud band is called the eyewall. The winds of a hurricane rotate in an anti-clockwise direction in the northern hemisphere and clockwise in the southern hemisphere. The speed and size of a hurricane depend on its environment, which includes factors such as the temperature of the water it moves over, wind shear (changes in wind speed with height), steering currents, and the Gulfstream.
A hurricane can strengthen rapidly, especially when it is moving over warmer ocean waters and near land. Research suggests that climate change is making this process faster and more frequent, as is the occurrence of major hurricanes (Category 3 or higher) close to shore. When a hurricane hits land, it loses its fuel and weakens, but it can still pack dangerous winds that destroy buildings and create monster storm surges. The heavy rains from hurricanes can also cause flooding, mudslides, and other damage as they move inland.