Each year in the Atlantic Ocean off of Africa’s west coast the prime conditions for the formation of hurricanes that affect the northern hemisphere of the United State comes to life.
Between June 1st and November 30th the Sahara Desert being one of the hottest places in the world gives birth to winds that travel across Africa and then drops into the Atlantic Ocean warming the waters to eighty degrees Fahrenheit or more. Along with these equatorial winds and warm waters, the prime environment for a hurricane evolves. This transformation begins when a tropical depression turns into a tropical storm; and then with the right conditions, this tropical storm can turn into a hurricane. (In the southern hemisphere these storms appear between December and April).
Thunderstorms develop and merge creating a low pressure system that hovers over the warm waters of the tropics. The process of evaporation occurs when these systems draw in moist air and thermal energy from the ocean’s surface making the air and clouds very humid. This causes winds to form and rise against each other spiraling upwards and passing through the thunderstorms. When these winds reach gale force they start to spin the clouds which then turns these depressions into tropical storms. A hurricane occurs when this formation becomes almost perfectly circular, covers an area of at least 500 miles in circumference and begins to spin at least 74 mph. As these storms merge the low pressure system in the center will eventually become the “eye”; thus the hurricane begins to rotate and move in a counterclockwise direction as it moves westward toward the pole. (In the southern hemisphere it will move in a clockwise direction. These storms are usually where cyclones and tropical typhoons appear).
As the hurricane begins to spin it gains strength and momentum by extracting warm air from the ocean and releasing cool air up and out though the top. After the storm reaches a height of 10,000 feet above the ocean’s surface the release of this condensation and latent heat is what forms the cloud bands that can be seen on radar.
The eye of the hurricane is often thought to be safe because the temperature is about 10 to 15 degrees Fahrenheit warmer and it appears to be calm; this can be very deceiving. Many will venture out to see what damage has occurred, but the wall around the eye is where the strongest winds and the most rain occur; and depending on the speed of the storm, this wall can appear unexpectedly. Once the eye passes, the power of the winds on the back side of a hurricane are more devastating and destructive.
Without warm water the hurricane can not survive. After it strikes land it looses momentum and eventually dies out but not before causing extensive damage to lives and land. The intensity of a hurricane can wipe out cities and their populations. It will spawn tornados, flooding and even tsunamis before losing its strength.
Hurricanes are to be feared. They are monstrous and unmerciful to all that lie in their paths. The devastation they leave behind stays long after they are gone.
Sources:
http://meteorologyclimatology.suite101.com/article.cfm/how_do_hurricanes_form
http://www.infoplease.com/ce6/sci/A0828957.html#axzz0wKfJpnJS
