Some of the greatest and most powerful storms on Earth are hurricanes. In fact, the energy of one hurricane is almost equivalent to a year's supply of electrical energy in the United States.

Hurricanes are violent, whirling storms that have sustained wind speeds above 74 miles (119 kilometers) per hour and up to 185 miles (300 kilometers) per hour. U.S. meteorologists calculate sustained winds by taking the average of the wind speeds they observe over a period of one minute. These winds are very different from the gusts you feel outside on a cool fall day. These gusts are strong, sudden bursts of wind.

Most of our planet's hurricanes are born in tropical oceans between 5 degrees latitude and 20 degrees latitude. Some hurricanes develop off the coast of Africa. They travel westward making their way to the Caribbean Sea or up the eastern coast of North America. As hurricanes cross the oceans, they can produce 50-foot (15-meter) waves. These same waves can cause tremendous damage hundreds of miles away from their starting point. Once hurricanes reach land or make landfall, they cause a huge number of deaths and injuries.
The strong winds, torrential rain, and massive flooding destroy property which will require billions of dollars to restore.

The easiest way to describe a hurricane is to compare it to an engine that needs continuous heat to work. For hurricanes, this heat comes from the condensation of large amounts of warm water vapor. When this water vapor is condensed, the heat is released into the air. This heated air gives the hurricane the buoyancy or lift it needs to move over oceans and land. As this process occurs, there is an area of low pressure near the surface. When there is low pressure, this means that air is rising. In the case of a hurricane, the air is rising rapidly. In contrast, areas of high pressure occur when air is sinking. Hurricanes need the warm, moist tropical air to build strength and to continue their journey across the oceans towards land.

Hurricanes usually form during the late summer months or during hurricane season. This is the time when these storms and other types of tropical storms are more likely to occur. Tropical storms are formed over warm oceans. They contain winds that blow between 39 and 73 miles per hour. If the wind increases during a tropical storm, a hurricane may develop.

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