Perhaps one of the most terrifying and destructive forces of nature is the hurricane. The hurricane can cover a wide area of land and sea while creating full destructive forces. It brews for days out in the ocean due to the warm temperatures; then once it hits land, pours rain with vengeance and hurls tornado force wind constantly on the land.
But hurricanes seldom form, and in contrast to thunderstorms are scarcely seen. What must be in place for a hurricane to develop? First the temperature and other factors must be at the utmost for a hurricane to develop.
The water must be at the correct temperature to produce a hurricane.
-The water must be a large area of the ocean and be at least 27 degrees Celsius or 80 degrees Fahrenheit. However no hurricanes are known to develop at the equator where these temperatures are common.
This is often known as "pre-birth" as this will produce a tropical depression. A tropical depression is not strong enough to be considered for a name. The winds in the storm are less than 34 mph.
-The troposphere must have slight winds flowing through it to create a low level disturbance, also known as a low area of pressure. However the upper atmosphere must have a high area of pressure well above the surface disturbance. The winds in the system will begin swirling most likely in a counterclockwise motion.
This, and a sustained wind speed of above 34 mph, will upgrade the storm to a tropical storm and be named.
Hurricane names alternate back and forth from female to male and follow the alphabet. Once a large storm is named and makes a destructive appearance, the name will be retired. Such as Andrew, (Miami, Florida, 1992) Katrina (New Orleans 2005).
-If the storm continues to move along and pick up warm moisture in the air it will continue to grow and gain strength.
Once the storm has a defined eye, in the center of the swirling winds, and is able to keep the winds sustained above 74 mph, the storm is again upgraded to a hurricane where it is put into different categories. There are five categories on the Saffir-Simpson hurricane scale.
1. 74-95 mph sustained winds produce 4-5 foot sea surges, but no real damage to building structures. Small damage may be inflicted to unanchored objects. Some minor flooding is expected.
2. 96-110 mph sustained winds produce 6-8 foot sea surges, with small damage to building structures. Vegetation will receive considerable damage. Flooding will damage piers and small boats in unprotected moorings.
3. 111-130 mph sustained winds produce 9-12 foot sea surges, with structural damage to small buildings. Mobile homes are destroyed. Flooding will be common near the coast with terrain flooded well inland.
4. 131-155 mph sustained winds with 12-18 foot high sea surges. Extensive damage can be seen on structures with small residences losing their roves. Major flooding will cause erosion of beach areas. Inland will begin to flood extensively.
5. 155+ mph sustained winds with 18+ foot sea surges. Roofs will be torn off of residences and industrial buildings. Small buildings will be blown away and complete building failures will be evident. Flooding will cause major damage to all houses that remain near the shoreline. Massage evacuation will most likely be enforced.
Once the afore mentioned ingredients gather, the time is right for the hurricane to develop. Though hurricane season is from June to November, hurricanes can develop anytime the weather is warm enough. Once the winds converge and begin to rotate around an area of disturbed weather a tropical disturbance is born. If the wind speed reaches 39 mph, the storm is upgraded to a tropical depression. Once it reaches 39-74 mph, it is again upgraded to a tropical storm and is named. If sustained winds are above 74 mph, the system is officially called a hurricane. Once the above circumstances are met and maintained, the intensity of the storm will remain constant or even intensify.
The average life span of a hurricane is 9 days, but it can run through all of the above in less than a day or sustain it for numerous days. Tropical Cyclone Ginger was the longest recorded hurricane, lasting 31 days from September 5th, to October 5th, 1971.
Once the hurricane has reached its full force, many side effects are brought into play. High winds, and torrential rain are the most common effects of the storm. Until the warm source of water is taken away, the hurricane can continue to produce these effects. Once on land a storm can slowly fizzle out, but often will continue as a large thunderstorm with rain and wind.
Hurricanes have brought large cities to a standstill. Nothing can be done to stop the force, and only preparing for disaster will not be sufficient. One must be able to understand the strength of the hurricane and be awed by it. The life cycle of a hurricane is large by storm standards and is perhaps one of the most dangerous natural phenomenons on the earth today.