hurricane, Weather And Climate: Terms And Concepts

Related Category: Weather And Climate: Terms And Concepts

Hurricanes and typhoons usually move westward at about 10 mph (16 kph) during their early stages and then curve poleward as they approach the western boundaries of the oceans at 20° to 30° lat., although more complex tracks are common. In the Northern Hemisphere, incipient hurricanes usually form over the tropical Atlantic Ocean and mature as they drift westward; hurricanes also form off the west coast of Mexico and move northeastward from that area. An average of 3.5 tropical storms per year eventually mature into hurricanes along the east coast of North America, usually over the Caribbean Sea or the Gulf of Mexico between June and November; one to three of these approach the U.S. coast annually, some changing their direction from west to northeast as they develop. Hurricanes and typhoons of the N Pacific usually develop sometime between May and December; typhoons and tropical cyclones of the Southern Hemisphere favor the period from December through April; Bay of Bengal and Arabian Sea tropical cyclones occur either between April and June or September and December, the times of the onset and retreat of the monsoon winds.