A hurricane is one type of a tropical storm that is a circulation of winds that form on the surface of a body of water accompanied by thunderstorms. There must be a surface temperature greater than 80 degrees, and a little wind shear has to be taking place in order for a hurricane to form. A wind shear is when there is a difference in speed and direction between the winds at upper and lower elevations. The winds, of a hurricane, rotate in a circular, counter clockwise direction around the eye of the storm. The eye of the storm is the center which is the calmest part with very little activity. The winds around the eye of the storm can reach up to 200 miles per hour and the damaging winds can extend 250 miles out from the eye of the storm.
The storm which produces hurricanes have different names depending on where the storm is located. The storms are referred to as tropical cyclones if they take place near Australia and in the Indian Ocean. The storms are referred to as typhoons if they take place in the Northwest Pacific Ocean, west of the International Date Line, which is an imaginary line and the same storm is referred to as a hurricane if they take place in the North Atlantic Ocean, the Caribbean Sea, the Gulf of Mexico, or the Northeast Pacific Ocean.
The life of a hurricane is divided into 4 stages, which are:
1. tropical disturbance
2. tropical depression
3. tropical storm
A tropical disturbance is an area where rain clouds are forming and a thunderstorm is developing causing heavy rains.
A tropical depression is when an area of low pressure that is surrounded by winds have begin to blow in a circular motion.
A tropical storm has been produced when the winds exceed a speed of 38 miles per hour. At this point, the storm clouds and the winds have formed a well defined circular pattern and the waters have become so rough that all water vessels need to stay clear of this area.
The storm has become a hurricane when the winds exceed a speed of 74 miles per hour. At this point, you can see a definite eye in the middle of the storm which is surrounded by a well defined circular shaped winds. The speed of the winds are determined by the size of the eye. The smaller the eye, the faster the speed of the winds, and the wider the eye the slower the speed of the winds. Hurricanes can last between 3 to 14 days, traveling along a 3,000 to 4,000 mile area at the speeds between 10 to 20 miles per hour.
When a hurricane hits land, the damage is caused by fast, fierce winds, heavy raining, rapid rise in the sea level causing killer storm surges, flooding, and huge waves that ultimately destroys the coast line and any homes or businesses in its way. A storm surge is when winds drive ocean waters ashore. In 1970, a cyclone hit East Pakistan, which is now Bangladesh, produced a surge that killed about 266,000 people. In the 1900's, a hurricane hit Galveston, Texas producing a surge that killed about 6,000 people.
The Saffir-Simpson Scale is a scale used to rate hurricanes intensity and destruction level. The scale was developed by and American engineer, Herbert S. Saffir. The scale groups hurricanes into 5 categories with category 1 being the weakest and category 5 being the most destructive. Examples of hurricanes that were ranked in category 5, are Hurricane Camille, which hit the United States in 1969, Hurricane Gilbert, which hit Mexico and the West Indies in 1988, and Hurricane Andrew, which hit Louisiana, Florida, and the Bahamas in 1992.