Hurricanes are violent storms in the air, which is known by different names by the people like typhoons or cyclones but only
tropical cyclones that form
over the Atlantic Ocean or eastern Pacific Ocean are called "
hurricanes."
Hurricanes develop in warm, tropical regions with moist air and converging equatorial winds where the water is at least 80 degrees Fahrenheit. A hurricane's low-pressure center of relative calm is called the
eye. It is generally 20 to 30miles wide. The area surrounding the eye is called the
eye wall, where the storm's most violent winds occur. At the top of the eyewall (up to 50,000feet), most of the air is propelled outward, increasing the air's upwardmotion. Some of the air, however, moves inward and sinks into the eye,creating a cloud-free area. As the storm system rotates faster and faster, an eye forms in the center. It is very calm and clear in the eye, with very low air pressure. Higher pressure air from above flows down into the eye. When the winds in the rotating storm reach 39 mph, the storm is called a "tropical storm." And when the wind speeds reach 74 mph, the storm is officially a "tropical cyclone," or hurricane.
Hurricanes are classified into
five categories, based on their
wind speeds and potential to cause damage.
- Category One—Winds 74-95 miles per hour
- Category Two—Winds 96-110 miles per hour
- Category Three—Winds 111-130 miles per hour
- Category Four—Winds 131-155 miles per hour
- Category Five—Winds greater than 155 miles per hour
In the U.S., the official hurricane season is from June 1 to November 30, but hurricanes can happen any time of the year. Hurricanes are named by the National Weather Service.