Types and Categories of Hurricanes - Term Paper Example

Running Head: HURRICANES Hurricanes Name Course Lecturer Date Introduction Hurricanes are among the world’s most complex natural phenomenon’s that have adversely affected the lives of many people across the globe. Although hurricanes have been witnessed in many parts of the world, the United States is the worst hit victim of this catastrophe. Considering the magnitude and complexity of hurricanes, meteorologists and other researchers have concentrated on this area to investigate the causes, developmental stages and implications of hurricanes. The paper seeks to explore the issue of hurricanes with regard to its definition, causes and developmental stages, history with reference to Florida estate, categories and characteristics, hurricane destruction power and major disasters caused by hurricanes. History of hurricanes in Florida Hurricanes have made history in the state of Florida. The state has witnesses some of the costliest and most intense hurricanes in the world. The first hurricane in Florida occurred in 1906, killing about one hundred people who worked in the Florida Keys. The hurricanes proceeded to the Pensacola area where it further killed 34 people. Other hurricanes occurred in 1909, 1910 and 1919 which caused massive damage on the Key West and Seven Mile Bridge. In 1921, a hurricane hit Florida central west coast and Tampa causing damages of over one million dollars. The storm exited at Jacksonville. The Okeechobee hurricane occurred in 1928 across the Palm Beach causing massive destruction and deaths of about 2000 people. In 1935, Florida witnessed one of the costliest and most intense hurricanes to have hit the United States. Speed of the wind was estimated to have been about 250 miles per hour and was classified as in category 5 of storms. It caused complete destruction of the Keys and killed all the workers who had been working on them. Florida was spared from hurricanes for 27 years until 1992 when the Hurricane Andrew hit and caused destruction of over 25 million dollars. Subsequent hurricanes were Hurricanes Frances, Jeanne and Wilma which occurred in 2004, 2004 and 2005 respectively. This history clear indicates that Florida is quite prone to hurricanes which are associated to its geographical location by meteorologists. It has subsequently triggered interventions by the Federal Government which is working closely with the Department of Meteorology to try curbing the situation or at least alleviating the adverse effects of the hurricanes (Barnes, 2006). Figure 1: major hurricanes that have hit Florida since 1851 Definition of hurricane A hurricane is a form of tropical cyclone. Tropical cyclones are systems of low pressure and are characterized by thunderstorm activity and counterclockwise rotation. Hurricanes commonly occur in the Gulf of Mexico, Southern Atlantic Ocean, Caribbean Sea and the Eastern Pacific Ocean. All the coast lines along the Atlantic and the Gulf of Mexico are subject to hurricanes. Effects of the hurricane spill off to the Pacific Ocean and Southern United States causing floods and heavy rains. Atlantic hurricane season occurs between June and November where the peak is between mid-August and October. On the other hand, Eastern Pacific season starts on May 15 and ends on November 30. Hurricanes produce fierce winds, microbursts and tornados that cause massive destruction to the inland in addition to destruction of the coastline (Chambers, 2006). Development of hurricanes Thunderstorms form the basis for the formation of hurricanes. Thunderstorms grow to the full strength of a hurricane with cooperation of the atmosphere and the ocean. The first requirement is that the ocean water must attain a temperature of 26.5 degrees Celsius and above. Moisture and heat from this water serves as the energy source for the hurricane. This is the reason why hurricanes rapidly weaken as they progress towards the dry land or over oceans where temperatures are cooler and moisture is insufficient. In light of this factor, middle and lower troposphere are therefore fundamental in hurricane development since they are characterized by high relative humidity. The high humidity reduces cloud’s evaporation, causes more precipitation and increases the latent heat. Increased latent heat is a major driving force of the system. Wind shear also plays an essential role in hurricane formation. Wind shear refers to the amount of change in wind speed and direction with increase in altitude. Weak wind shears enhance vertical growth of the storms and ultimate release of latent heat into the air above the storm thus aiding hurricane development. Evolution of hurricanes occurs in a series of stages from inception to death. A tropical disturbance may become intense if it acquires a specified and prolonged wind speed. Figure 2: Developmental stages of a hurricane from the tropical depression to the tropical storm and finally to the hurricane. Tropical depression: It is basically an organized system of thunderstorms and clouds characterized by winds with specific surface circulation and sustained wind speed of about 38 mph. tropical depressions can be numbered either as tropical storm watch where conditions of a tropical storm are seen within 36 hours or tropical storm warning where conditions are predicted within 24 hours. Tropical storm: It is an organized system of thunderstorms which are stronger than tropical depression and a sustained wind speed of 39-73 mph. Hurricane: They contain strong thunderstorms and sustained wind speed of over 74 mph. Hurricane characteristics and categories Typical hurricanes have a width of 300 miles but this varies considerably. It contains an eye which is basically crosses the center of the hurricane at about 20-40 miles. The eye is relatively calm. The eye is surrounded by the eyewall which is made of dense clouds and the highest number of winds in the storm. The outer rainbands of the storm are composed of dense bands of strong thunderstorms ranging from a few miles wide to about 300 miles long. Outward extension of hurricane-force winds for small winds is 25 miles and for large ones is 150 miles. In many cases, storm winds, tornadoes and surges are caused by the right side of the hurricane. Weather patterns, complex atmospheric and ocean interaction determine hurricane path and speed. Figure 3: The structure of a typical hurricane Hurricanes are classified into five categories; 1) in category one, damages are minimal, maybe mere destruction of plants and low road floods; 2) in category 2 damages are moderate, involving damage of some buildings and major destruction on trees and plants while floods occur about 2-4 hours prior to the storm; 3) in category 3 extensive damages are witnessed, telephone lines are disengaged and flooding may be go up to 5 foot above sea level; 4) in the fourth category, damages are quite extreme as roofs are completely blown off and floods are about 10 feet above sea level 5) and in category 5, damages are quite catastrophic where building especially those in the coast lines are brought down and the place becomes completely flooded (Longshore, 2008). Hurricane hazards The main hazards associated with hurricanes are high winds, storm surge, flooding, heavy rains and tornadoes. Damage potential is determined by the intensity of the hurricane. A storm surge is a large water dome that extends between 50-100 miles wide. It occurs across the coastline where it makes a landfall of the hurricane. Storm surge pose are major threats to property and life. Hurricane winds have devastating damages on structure and life due to the amount of debris they carry. They begin before the formation of landfall by the hurricane eye. Huge amounts of rainfall, at least 6 to 12 inches are frequently produced by typical hurricanes. This results to flooding and subsequent destruction of property and loss of life. In mountainous areas, hurricanes can lead to devastating mudslides. Tornadoes are formed just at the fringe of the storm and cause enormous damages. Besides, this direct implications if hurricanes there are other indirect consequences that have been linked to hurricanes. They include health complications such as heart and panic attacks, fires and electricity failures (Emanuel, 2005). Major disasters caused by hurricanes in Florida The hurricane Andrew which occurred in 1992, was a category 5 hurricane and was considered as one of the most devastating catastrophes of the time. It led to complete leveling of homesteads, commercial buildings and damaging of the West Keys. It was estimated that damages exceeded the combination Hugo, Betsy and Agnes hurricanes which cost more than 25 billion dollars. Other major hurricanes in the history of US are Galveston, Lake Okeechobee, Cheniere Caminanda, Katrina and Sea Island. They caused massive destruction and loss of lives of many people. Conclusion Hurricanes are catastrophic phenomenon that remains to be a pressing issue among the affected nations. Although they occur in several places especially those in the coastlines of the Pacific and Atlantic oceans, the United States is clearly the worst hit. In particular, the Florida state has made history in hurricane occurrence. This has attributed to its geographical location. Hurricanes are formed in a cycle of stages; the tropical depression, tropical storm and the actual hurricane. It is also clear that hurricanes are caused by the combination of factors including thunderstorms, moisture and latent heat. A typical hurricane is characterized by basic features such as the eye, eyewall and rainbands. Hurricanes cause major hazards such as heavy rain, flooding, storm surge and tornadoes. Hurricanes are quite disastrous in terms of property destruction and loss of life. References Emanuel, K. (2005). Are there trends in hurricane destruction? Nature, volume 438, Issue 22, p. 686-688. Barnes, J. (2006). Florida’s hurricane history. Chapel Hill: University of the North Carolina press. Chambers, C. (2006). Hurricanes. Brighton: Book House. Longshore, D. (2008). Encyclopedia of hurricanes, typhoons, and cylones. New York: Facts on Files. 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