A hurricane is a type of tropical cyclone that produces disturbances known as tropical waves which occur every few days in the warm coastal waters during hurricane season (June 1 to November 30.)
~ Pre Birth Stage
In order for a hurricane to reach the first stage birth, a few conditions must be present; water temperature of 80 degrees that reaches a depth of at least 125 feet, light winds with a low wind shear and a tropical disturbance that produces thunderstorms.
When these conditions are right a tropical depression is formed which is an organized storm system that produces thunderstorms. Putting moisture in to the air. With the right amount of clouds and moisture in the warm air a tropical storm now forms which is a more organized storm with heavy thunderstorms and winds up to 73 miles an hour.
One of two things will happen after the tropical storm develop; it will run its course and die out or it will pick up stronger winds, more precipitation and turn in to a hurricane.
~ Birth Stage
A tropical storm becomes a hurricane when the heat and moisture from the ocean combine with the light wind near the surface of the ocean during a low pressure system.
The light winds are “sucked” in to the system and begin swirling in a counterclockwise motion. As the storm travels it picks up more moisture and releases more heat which allows for the hurricane to continue
Once it has reached sustained winds of 74 miles per hour and has formed a circular cloud pattern that continues to grow as it moves across the ocean. It is now a well developed hurricane with all three components; the rain bands, eye wall and the eye of the hurricane.
~ Growth
The hurricane will most often continue to grow in size and strength as it moves across the ocean picking up more moisture and heat as it travels. A strong well organized hurricane can “survive” for over two weeks at sea if the conditions remain in its favor.
~ End of the Life cycle
A hurricane can end well before it reaches landfall, a wind shear can destroy the organization of the hurricane breaking it up. Cooler water temperate and less moisture will also break up a hurricane that is still at sea.
Once a hurricane hits land there is no more “added” moisture from the ocean, so all it has left to use is what it is the rain bands and eye wall.
~ Longest Living Hurricanes
* Hurricane John, in 1994 – lasted 31 days, he crossed the international dateline not once but twice! He reached category 5 status and traveled over 8000 miles. When he did make finally landfall in Hawaii and Johnston Island Navy base in the United States the storm was barley a measurable severe thunderstorm.
* Hurricane Ginger, in 1971 – lasted 28 days in the North Atlantic Ocean. Making her dbut as a category 3 hurricane in North Carolina on October 5.
The life cycle of a hurricane varies with each storm the average life span of a hurricane is five to seven days.
Sources
http://www.sun-sentinel.com/news/weather/hurricane/sns-hc-history-2000,0,6703346.story
http://hurricanes.noaa.gov/pdf/hurricanebook.pdf
http://www.aoml.noaa.gov/hrd/tcfaq/E6.html
