Where do tropical cyclones form?
Tropical cyclones form in the north Atlantic, northern Pacific Ocean, southwestern Pacific, and Indian Ocean. They may rarely form elsewhere in the world. The Atlantic Ocean has around ten hurricanes each year. They can hit Central America, Mexico, the United States, Canada, Bermuda Island, and the Caribbean Islands. Most hurricanes form between June and November. Tropical cyclones rarely form in the south Atlantic. The northeastern Pacific has around sixteen cyclones a year between May and November, most of which do not hit land. Meanwhile, the northwestern Pacific has around 27 cyclones a year, usually hitting Japan, China, Korea, Taiwan, the Philippines, and some Pacific islands. This area has typhoons all year round. The northern Indian Ocean has around six cyclones a year, usually hitting India, Bangladesh, and Pakistan, as well as nearby countries. Cyclones form year-round in this area.
Tropical cyclones generally form in any ocean where water temperatures are greater than 80 degrees Fahrenheit and the upper-level winds are benign. Here are oceans where they can form and their commonly used names: • North Atlantic (including Caribbean and Gulf of Mexico): Hurricanes • Eastern and Central North Pacific: Hurricanes • Western Northern Pacific: Typhoons • Arabian Sea/Northern Indian Ocean: Tropical Cyclones • South Indian Ocean: Tropical Cyclones/Willy-Willy for southwest Australia • Coral Sea/South Pacific: Tropical Cyclone There are several tropical oceans where colder water currents and strong upper-level winds usually prevent tropical cyclones from forming. These locations include the parts of the Atlantic Ocean near the African coast and south of the Equator and Pacific Ocean off of the South American Coast. However, a rare tropical cyclone did form just off the Brazilian Atlantic Coast in March 2004.
Nearly all tropical cyclones form within 30 degrees of the equator and 87% form within 20 degrees of it. However, because the Coriolis effect initiates and maintains tropical cyclone rotation, such cyclones almost never form or move within about 10 degrees of the equator (where the Coriolis effect is weakest). However, it is possible for tropical cyclones to form within this boundary if another source of initial rotation is provided. These conditions are extremely rare, and such storms are believed to form at a rate of less than one a century. Most tropical cyclones form in a worldwide band of thunderstorm activity known as the Intertropical convergence zone (ITCZ). Worldwide, an average of 80 tropical cyclones form each year.
The tropical cyclones form over ocean basins in lower latitudes of all oceans except south Atlantic and southeast Pacific. The tropical cyclones develop over the warm water of the Bay of Bengal and the Arabian Sea. The favourable ocean basins for development of cyclonic storms are shown in the figure below. TC breeding grounds are located over certain ocean basins. Arrows indicate average trajectories over different basins What is the size of a tropical cyclone over the north Indian Ocean The size of a tropical cyclone over Indian seas varies from 50-100 km radius to 2000 km with an average of 300 600 km.
