A hurricane is a powerful tropical storm with strong winds, high waves, and heavy rains. In various parts of the world, hurricanes have different names: around the Pacific Ocean, they are called typhoons; and around the Indian Ocean, they are called cyclones. The powerful wins and the heavy rainfalls of hurricanes often cause destruction when the immense storms reach land. Winds can destroy lives and property; heavy rains can generate floods. A hurricane’s strength is measured by its intensity, which is determined by the wind speed. The Saffir-Simpson scale rates the severity from category one to five, with five being the strongest. Because hurricanes can be so deadly and destructive, warnings are now issued within twenty-four to thirty-six hours of the storm’s arrival in a coastal area.
Hurricanes form in areas near the equator where the air is warm and moist. Thunderstorms and tropical depressions (areas of low pressure) help start the formation of hurricanes. The moisture in the extremely humid air around these storms condenses into rain and gives off heat. This heat warms the air and begins to rise. As the warm air rises, it begins to spin and form tight curls. (In the Northern Hemisphere, the air spins counterclockwise; in the Southern Hemisphere, the air spins clockwise.) This mass of whirling air can gow for several days. As it grows, it can range from about 20 to 1,000 miles in diameter. The curls form a circle around the center of the hurricane, which is called the eye. In the eye, the weather is calm. Around the eye, however, heavy rains and high clouds form. As the storm grows and strengthens, the air begins to move forward at speeds around ten miles an hour. When the storm moves away from the equator, it speeds up to thirty or forty miles an hour. The winds within a hurricane can range between 74 and 200 miles per hour, but as the hurricane comes closer to land, it becomes weaker because it moves away from its energy source: the warm water. Then, land and wind cause friction, and this slows down and breaks apart the hurricane. Even when this happens, however, it is important to remember that the remaining winds and rains are still extremely powerful and destructive forces of nature.
