Hurricanes, Typhoons, and Cyclones

Factors involved: Geography, gravitational forces, rain, weather conditions, wind

Regions affected: Cities, coasts, forests, islands, oceans, rivers, towns

Definition

Hurricanes, typhoons, and cyclones are storms formed over tropical oceans. A single storm can cover hundreds of thousands of square miles and have interior winds from 74 to over 157 miles per hour. Hurricanes are known as the “greatest storms on earth,” and their destruction goes beyond wind damage, as storm surges and subsequent flooding have accounted for many of the greatest natural disasters in the world. Hurricane damage in the United States continues to rise as more people move to coastal areas and as hurricanes become more intense; however, the loss of life decreased over time because of better forecasting and evacuation methods.

Science

A hurricane (from the Caribbean word huraka’n), also called a typhoon (a combination of t’ai feng, Chinese for “great wind,” and typhon, Greek for “whirlwind”), requires warm surface water, high humidity, and winds from the same direction at a constant speed in order to form. All hurricanes begin as cyclonic tropical low-pressure regions, having a circular motion that is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. These depressions can develop only in areas where the ocean temperatures are over 75 degrees Fahrenheit (24 degrees Celsius). The eye structure of a hurricane, which must be present in order for a storm to be classified as a hurricane, demands temperatures of 79 to 80.6 degrees Fahrenheit (26 to 27 degrees Celsius) to form.

In hurricane formation, heat is extracted from the ocean, and warm, moist air begins to rise, or evaporate. As it rises, it forms clouds and instability in the upper atmosphere. The ascending air then begins to spiral inward toward the center of the system. This spiraling movement causes the seas to become turbulent; large amounts of sea spray are then captured and suspended in the air. This spray increases the rate of evaporation and helps fuel the storm.

As the vortex of wind, water vapor, and clouds spins at an increasing rate, the eye of the hurricane forms. The eye, which is at the center of the hurricane, is a relatively calm area that experiences only light winds and fair weather. The most violent activity in the hurricane takes place in the area around the eye, called the eyewall. In the eyewall, the spiraling air rises and cools and moisture condenses into droplets that form rainbands and clouds. The process of condensation releases latent heat that causes the air to rise and form more condensation. The air rises rapidly, resulting in an area of extremely low pressure close to the storm’s center. The severity of a hurricane is often indicated by how low the pressure readings are in the central area of the hurricane.

As the air moves higher, up to 50,000 feet, it is propelled outward in an anticyclonic flow. At the same time, some of the air moves inward and into the eye. The compression of air in the eye causes the temperature to rise. This warmer air can hold considerable moisture, and the water droplets in the central clouds then evaporate. As a result, the eye of the hurricane becomes nearly cloud-free. In the middle and upper levels of the storm, the temperature in the eye becomes much warmer than the outside. Therefore, a large pressure differential develops across the eyewall, which helps to produce the violence of the storm.

The hurricane winds create waves of fifty to sixty feet in the open ocean. Winds in a hurricane are not symmetrical around the eye. Facing the direction the hurricane is moving, the strongest winds are usually to the right of the eye and can move at speeds up to two hundred miles per hour. The radius of hurricane winds can vary from ten miles in small hurricanes to one hundred miles in large hurricanes. The strength of the wind decreases in relation to its distance from the eye.

Depending on the size of the eye, which can range from three to forty miles in diameter, a calm period of blue skies and mild winds can last from a few minutes to hours as the eye moves across a given area. The calm is deceptive because it does not mark the end of the storm but a momentary lapse in intensity until the winds from the opposite direction hit.

Storms resembling hurricanes but that are less intense are classified by their central pressure and wind speed. Winds up to 39 miles per hour (34 knots) are classified as tropical depressions, and winds of 40 to 73 miles per hour (35 to 64 knots) are called tropical storms. To be classified as a hurricane, storms must have sustained winds of 74 miles per hour or higher.

All hurricanes in the Northern Hemisphere have a general track, beginning as a westward movement in response to the trade winds, veering northward because of anticyclonic wind flow around subtropical high pressure regions, and finally trending northeastward toward polar regions in response to the flow of the prevailing westerly winds. The specific path that each storm travels is very sporadic. Some will travel in a general curved path, while others change course quite rapidly. They can reverse direction, zig-zag, veer from the coast back to the ocean, intensify over water, stall, return to the same area, make loops, and move in any direction at any given time.

The path of a hurricane is affected by pressure systems of the surrounding atmosphere and the influence of prevailing winds as well as the earth’s rotation. Hurricanes can also be influenced by the presence of high and low pressure systems on the land they invade. The high pressure areas act as barriers to the hurricanes, and if a high is well developed, its outward spiraling flow will guide the hurricane around its edges. Low pressure systems tend to attract hurricane systems.

The greatest cause of death and destruction in a hurricane comes from the rise of the sea in a storm surge. As the hurricane crosses the continental shelf and moves to the coast, the water level may increase 15 to 20 feet. The drop in atmospheric pressure at sea level within the hurricane causes the storm surge. The force of the reduced pressure allows the hurricane to suck up the seas and to allow the winds in front of it to pile up the water against the coastline. This results in a wall of water that can be up to 20 feet high and 50 to 100 miles wide. This wall of water can sweep across the coastline where the hurricane makes landfall. The combination of shallow shore water and strong hurricane winds makes for the highest surge of water.

If the storm surge arrives at the same time as the high tide, the water heights of the surge can increase an additional 3 to 4 feet. The height of the storm surge also depends upon the angle at which the storm strikes the coast. Hurricanes that make landfall at right angles to the coast will cause a higher storm surge than hurricanes that enter the coast at an oblique angle. Often the slope or shape of the coast and ocean bottom can cause a bottleneck effect and a higher storm surge. Rising sea levels may also contribute to larger storm surges.

Water weighs approximately 1,700 pounds per cubic yard, and when lifted to any great height its weight can be very destructive. The storm surge is responsible for 90 percent of the deaths in a hurricane. The pounding of the waves caused by the hurricane can easily demolish buildings. Storm surges can cause severe erosion of beaches and coastal highways. Often, buildings that have survived hurricane winds have had their foundations eroded by the sea surge or have been demolished by the force of the waves. Storm surges and waves in harbors can destroy ships. The salt water that inundates land can kill existing vegetation, and the residual salt left in the soil makes it difficult to grow new plants.

Precipitation from hurricanes can be more intense than from any other source. The amount of rainfall received during a hurricane depends on the diameter of the rain band within the hurricane and the hurricane’s speed. A typhoon in the Philippines in 1944 caused 73.62 inches of rain to fall in a 24-hour period, a world record. Heavy rainfall can cause flash floods or river system floods. Flash floods last from thirty minutes to four hours and are caused by heavy rainfall over a small area that has insufficient drainage. This causes excess water to flow over land and overflow streambeds, resulting in damage to bridges, underpasses, and low-lying areas. The strong currents in flash floods can move cars off roads, destroy bridges, and erode roadbeds.

River system floods develop more slowly. Two or three days after a hurricane, large rivers may overflow their beds because of excessive runoff from the saturated land surface. River floods cover extensive areas, last a week or more, and destroy both property and crops. When the floodwaters retreat, buildings and residences can be full of mud. Often, all furnishings, appliances, wallboard, and even interior insulation within the structure must be completely replaced because of the infiltration of the mud. Rain driven by the wind in hurricanes can cause extensive damage to buildings because of leakage around windows, through cracks, and under shingles.

Hurricanes often spawn tornadoes. The tornadoes associated with hurricanes are usually about half the size of tornadoes in the Midwest and are of a shorter duration. The area these tornadoes affect is small, usually 200 to 300 yards in width and not quite one mile long. Yet even though they are smaller tornadoes, they can be very destructive, ruining everything in their path. Tornadoes normally occur to the right of the direction of the hurricane’s movement. Nearly 95 percent of tornadoes occur within 10 to 120 degrees from the hurricane eye and beyond the area of hurricane-force winds. Tornadoes associated with hurricanes are most often observed in Florida, Cuba, the Bahamas, and the coasts of the Gulf of Mexico and the south Atlantic Ocean.

Geography

Because hurricanes require temperatures of 79 to 80.6 degrees Fahrenheit (26 to 27 degrees Celsius) to form, they have rarely developed above 20 degrees latitude because the ocean temperatures have never been warm enough to provide the heat energy needed for formation. In the Northern Hemisphere, the convergence of air that is ideal for hurricane development has occurred above tropical waters when easterly moving waves develop in the trade winds. The region around the equator is called the “doldrums” because there is no wind flow. Hurricanes, needing wind to form, can be found as little as 4 to 5 degrees away from the equator. At these latitudes, the Coriolis effect, a deflecting force associated with the earth’s rotation, gives the winds the spin necessary to form hurricanes.

Hurricanes evolve in specific areas of the west Atlantic, east Pacific, south Pacific, western north Pacific, and north and south Indian Oceans. They rarely move closer to the equator than 4 or 5 degrees latitude north or south, and no hurricane has ever crossed the equator. In the Northern Hemisphere, hurricanes are common from June through November; in the Southern Hemisphere, the hurricane season occurs from December to May.

In the Western Hemisphere, these storms are called hurricanes. They are referred to as typhoons in the western Pacific, cyclones in the Indian Ocean, Willy Willys near Australia, and baguious in the Philippines. The swirling motion of these storms is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere because of the Coriolis effect.

Prevention and Preparations

Hurricanes cannot be prevented; therefore, steps need to be taken to avoid loss of life and destruction of property. Persons in hurricane areas need to be aware of and respond to hurricane watches and warnings forecast by the National Hurricane Center, National Weather Service, and local media. The National Hurricane Center is responsible for forecasting hurricane watches and warnings for the Atlantic and eastern Pacific north of the equator. Although both warning capacity timing and accuracy have greatly improved, predictions can still be inaccurate by as much as 100 miles in a 24-hour period.

Before a watch or warning is forecast, residents need to prepare a home evacuation plan. This involves determining where the family will go if a hurricane threatens. The options include staying with friends or relatives outside the area or going to public shelters. Evacuation supplies such as extra cash, hygiene products, drinking water, batteries, bedding, clothing for wet and cold conditions, prescriptions, canned foods, and road maps should be kept on hand. A three-week supply for each person and pet is recommended. Restoration supplies should also be organized and stored together for use after residents are able to return home. Restoration supplies include rope and chains, brooms and shovels, rolls of heavy plastic, duct tape, tools, nails, pruning shears and saws, large-capacity garbage bags, nonperishable foods, folding lawn chairs, mosquito spray and netting, and chlorine bleach to be used for purifying water.

In order to protect homes in hurricane areas, shutters should be installed to protect windows. In some cases thin plywood can be used to cover large windows. Masking tape or duct tape applied to windows can help control some of the shattering in window breakage. Gas grills and propane gas tanks should be stored in a safe place so they are not damaged and do not explode during the storm. It is recommended that dead vegetation around the house be cleared and any coconuts be removed from the trees so that they do not become destructive debris in the midst of the hurricane. All objects kept outside should be tied down, and all electricity, water, and gas should be turned off at the main panel if a hurricane warning is issued. Insurance policies, inventory records, and important documents should be kept in safe-deposit facilities. Trees and shrubbery should be cut in such a manner as to allow air to flow through them so that they will survive in hurricane winds.

If a hurricane watch is issued, windows should be covered and backup systems such as portable pumps to remove floodwater, alternate power sources, and battery-powered lighting should be made available. Because a hurricane watch means that a hurricane is possible in 24 to 36 hours, residents should be prepared for evacuation if one is called.

A hurricane warning indicates that a hurricane will reach land within 48 hours. All utilities should be turned off and loose items secured. Small items inside the house should be placed on countertops in order to avoid damage in case of flooding. Cash, social security cards, drivers’ licenses, wills, medical records, bank account information, small valuables, and photo albums should be put in waterproof bags to ensure their safety. Garbage cans, lawn furniture, and bicycles should be brought inside. Cars should be fueled and should contain evacuation maps; if evacuation is called for, then emergency plans should be put into action.

One way to survive a hurricane is to build a “safe room” or shelter in the house. The shelter must be built where it cannot be flooded during a hurricane. It must be anchored to the foundation of the house in such a way as to resist uplift or overturning in the storm. All the connections in the shelter must be strong enough to resist structural failure and penetration by wind-blown debris.

Rescue and Relief Efforts

Devastation after a hurricane can range from light to catastrophic, depending on the storm’s intensity. Millions of cubic yards of debris can be left in a hurricane’s wake. Before residents are allowed to return to a hurricane area, emergency management personnel make search and rescue and preliminary damage assessments. Residents are not allowed back until the area is determined safe. Dangling wires, fallen trees, debris, and washed-out roads can make travel into the area difficult or impossible until cleanup has been accomplished.

Debris can consist of trees, shrubs, building materials, and hazardous waste, such as paints, solvents, batteries, and insecticides. As this debris is cleaned up, Emergency management and Environmental Resources Management personnel, with the help of the US Army Corps of Engineers, will need to authorize and manage the disposal of the debris. Task forces work with regulatory agencies to determine the impact of incineration and other disposal methods.

The Red Cross/Red Crescent and other volunteer agencies often help provide needed relief. Often there is deterioration or contamination of water supplies, and the Red Cross supplies bottled water as well as nonperishable foods. Shelters may be set up for those left without homes.

Residents are advised not to enter their homes or businesses before officials have checked for structural damage. They are told to beware of such outdoor hazards as downed power lines, weakened limbs on trees, or damaged overhanging structures. People need to be aware that poisonous snakes are often driven from their dens by high water and seek refuge in trees and structures. Residents are encouraged to take as many photographs of the damage to their property as possible for insurance purposes. If their homes are livable, the long process of cleanup begins.

Impact

The Saffir-Simpson Hurricane Scale categorizes the storm intensity of hurricanes into five levels. Category 1 hurricanes are considered weak and have sustained winds of 74 to 95 miles per hour. They cause minimal damage to buildings but do damage unanchored mobile homes, shrubbery, and trees. Normally they cause coastal road flooding and minor damage to piers. Storm surges seen in Category 1 hurricanes are usually 5 to 7 feet above normal.

Category 2 hurricanes, with wind speeds of 96 to 110 miles per hour, damage roofing materials, doors, and windows on buildings. They also cause substantial damage to trees, shrubs, mobile homes, and piers. Utility lines can be blown down, and vehicles may be blown off bridges. Flooding of roads and low-lying areas normally occurs two to four hours before the center of the hurricane arrives. Storm surges are estimated to be 8 to 12 feet high under these conditions.

Category 3 hurricanes are considered strong, with winds of 111 to 129 miles per hour; large trees can be blown down. These storms destroy mobile homes and can cause structural damage to residences and utility buildings. Small structures can be destroyed, and structures near the coastline can sustain damage from battering waves and floating debris. Flooding from this level of hurricane can destroy small structures near the coast, while larger structures normally sustain damage from floating debris. There can be flooding 8 miles or more inland. Coastal areas can sustain storm surges of 11 to 16 feet.

Category 4 hurricanes are categorized as very strong, with winds of 130 to 156 miles per hour. These storms can blow down trees, shrubs, power lines, and antenna towers. They cause extensive damage to single-family structures and cause major beach erosion. They can damage lower floors of structures, and the flooding can undermine foundations. Residences often sustain roof structure failure and subsequent rain damage. Land lower than 10 feet above sea level can be flooded, which would cause massive evacuation of residential areas up to 6 miles inland. Storm surges may reach 14 to 20 feet at this level.

Category 5 hurricanes are classified as devastating, sustaining winds greater than 157 miles per hour. Evacuations of residents living within 5 to 10 miles of the shoreline may be required. Such a strong hurricane can cause complete roof failure on residential and industrial buildings, as well as some complete building failures. Major utilities are usually destroyed in this level of hurricane. Structures less than 15 feet above sea level can sustain major damage to lower floors, and massive evacuations of residential areas usually occur. Storm surges associated with these severe hurricanes can be 18 feet or higher.

The devastation of hurricane winds is exemplified by the fact that the wind force applied to an object increases with the square of the wind speed. A building 100 feet long and 10 feet high that has 100-mile-per-hour winds blowing against it would experience 40,000 pounds of force being exerted against its walls. This is because a 100-mile-per-hour wind exerts a force of approximately 40 pounds per square foot. If the wind speed was 160 miles per hour, the force against the house would be 100,000 pounds. Additionally, winds in a hurricane do not blow at a constant speed. The wind speeds can increase and decrease rapidly. The wind pressure on the house and fluctuating wind speed can create enough stress to cause connections between building components to fail. Often the roof or siding can be ripped off the house, or windows may be pushed in. Structures that fail because of the effects of extreme winds often look as if they have exploded. Rain blown by the wind also contributes to an increase of pressure on buildings and can result in structural failure.

Flying debris, often referred to as “windborne missiles,” can be thrown at a building with enough force to penetrate the walls, windows, or roof. A 2-by-4-inch piece of wood that weighs 15 pounds can have a speed of 100 miles per hour when carried by a 250-mile-per-hour wind. This will enable it to penetrate most reinforced masonry.

The impact of hurricanes goes beyond the destruction of homes and property. Agricultural loss, oil platform and drilling rig damage, and destruction of boats can range into millions and even billions of dollars. Property loss alone in 1992's Hurricane Andrew was approximately $25 billion. Agriculture, petroleum industry, and boat losses in Florida and Louisiana amounted to another $1 billion. As of 2021, Hurricane Katrina (2005), Hurricane Harvey (2017), and Hurricane Maria (2017) were estimated to be among the most destructive hurricanes ever recorded, causing around $100 billion, $125 billion, and $96 billion in damages, respectively. The deadliest recorded storm was the Bhola cyclone of 1970, which brought a large storm surge to densely populated Bangladesh, killing at least three hundred thousand people.

The marine environment is also impacted by hurricanes. There can be changes in near-shore water quality, as well as bottom scouring and beach overwash. Fuel from damaged boats can discharge into the water for days. Often, sponges, corals, and other marine life will be severely impacted.

Historical Overview

Hurricanes are major tropical storms that originate in the Atlantic Ocean off the west coast of Africa between June and November. Similar storms can develop in the Pacific Ocean, where they are called typhoons, and in the Indian Ocean, where they are called cyclones. Hurricanes have clearly existed since the end of the last ice age, but their impact on humans has increased markedly with the growth of population in the coastal areas hit by these storms.

The Atlantic Coast and the coastline of the Gulf of Mexico are the two areas most affected by Atlantic hurricanes. The tail end of such a storm may have destroyed the remains of the Spanish Armada in 1588, when it sought to escape the victorious English fleet by sailing around the British Isles.

Hurricanes have had a profound impact on the vegetation of the Atlantic coastline. These “disturbances,” as ecologists classify them, have the effect of destroying so much of the vegetation that the process of ecological succession must start over in the areas affected by hurricanes. There is, on average, one hurricane per century at any particular point on the Atlantic coast; in the twentieth century, a Category 4 hurricane struck the Atlantic coast once every six years, on average.

What is known about hurricanes before the twentieth century comes mainly from descriptive records. It is known, for example, that what has been described as a hurricane struck the coastline of Rhode Island and Massachusetts in 1635, and another hit about a century later, in 1727. In 1752, the Carolinas were hit, and in 1769 and again in 1783 hurricanes struck the Atlantic coastline from South Carolina to New England. How much destruction was done by these hurricanes, or how many may have lost their lives, is unknown because records of that sort were not kept at that time.

Scientists are sure that a hurricane that missed New Orleans on August 13, 1856, wiped out the settlement on Last Island, off the Louisiana coast. The Federal Weather Bureau was created in 1890, and in 1898 an early warning network was set up in the West Indies—the first steps in the system that, by the end of the twentieth century, succeeded in reducing the loss of life from hurricanes. Notwithstanding, these early warning efforts did not prevent what is still, from the standpoint of loss of life, the most devastating hurricane in US history: the Galveston Hurricane that struck Galveston, Texas, on September 8, 1900. Estimates of the death toll (arising as much from the following storm surge) reach about twelve thousand.

Deaths by drowning are common features of some of the earlier known hurricanes, a hazard that has been mitigated by the evacuation of communities in the path of a hurricane. A storm that hit the Miami, Florida, area in 1926 left more than two hundred people dead. More than four thousand died in 1928 when, as a consequence of the storm named for it, Lake Okeechobee overflowed. This disaster, also known as the San Felipe hurricane, led to the construction of a levee around the lake.

Only forty-seven were killed in 1933 when a hurricane struck the mid-Atlantic coast. This hurricane led to further actions on the part of government to prevent the loss of life from hurricanes. Notwithstanding preventive measures, the 1930s had one of the most destructive hurricanes of the twentieth century, when the Great New England Hurricane of 1938 struck New England and pushed inland, killing more than six hundred people and causing extensive damage, particularly to the forests of New England. Even though this hurricane qualified as only a Category 2 storm, the extent of the damage etched it permanently in the minds of many New Englanders.

The radio made advance warning of large populations much easier as it became popular in the 1930s. World War II, however, with its extensive use of airplanes, revolutionized the handling of hurricane information. With airplanes, it became possible to fly over the disturbances as they progressed from the Atlantic Ocean off the coast of Africa toward the Atlantic coastline of the Western Hemisphere. It thus became customary to follow the path of a hurricane and to forewarn threatened populations by radio. Because the radio message was easier to understand when it had a name attached to it, the practice of naming hurricanes began in 1953.

In 1965, US president Lyndon Johnson reorganized the government’s weather monitoring system. Prior to that, in 1955, two new facilities were created: the National Hurricane Center in Miami and the Experimental Meteorology Laboratory, also in Miami. The latter performs meteorological research, and the former tracks the paths of hurricanes as they develop. They subsequently became part of the National Oceanographic and Atmospheric Administration (NOAA). In 1978, the Federal Emergency Management Agency (FEMA) was added by President Jimmy Carter to the governmental organizations designed to deal with hurricanes and other natural disasters.

The devastation wrought by Hurricane Camille, which struck the Gulf Coast on August 17, 1969, made clear the importance of united societal action. Although Camille caused only 258 deaths—as compared with predecessors Audrey in 1957, in which more than 500 people lost their lives, and Hilda, which killed 304 people in 1964—but the value of the property destroyed by Camille soared into the billions and focused people’s minds on the problem of hurricanes.

Hurricanes are quite erratic in where they strike land (they generally lose force quickly once they move over land), but the Gulf Coast has been a favorite target. In August 1970, Hurricane Celia struck Texas and Florida; in September 1979, Hurricane Frederic landed on the Gulf Coast (in 1979 men’s names as well as women’s began to be used), in 1985, Hurricane Juan struck the Gulf Coast, and in September 1988, Hurricane Gilbert hit the Caribbean and Mexico. In 1992, Hurricane Andrew hit chiefly South Florida but also went on to Louisiana, and in 1998 Hurricane Georges struck first in the Caribbean and then traveled to the Gulf Coast. In 2005, numerous strong hurricanes formed, with several striking the Gulf Coast. The worst by far was Hurricane Katrina, which devastated Louisiana, Mississippi, and Alabama and left as many as two thousand dead.

It has been found that the number of deaths caused by hurricanes can be reduced dramatically by evacuating the residents of an area in the path of a hurricane. If a hurricane strikes the coast of North America in a relatively uninhabited area, destruction will probably be extensive but few lives will be lost. However, the rapid growth of coastal populations makes it less and less likely that hurricanes will come ashore where there are few people. Even though Hurricane Hugo in 1989 struck a portion of the South Carolina coast that was lightly inhabited, it caused the deaths of seventy-five people; the more intense Hurricane Andrew resulted in the deaths of only fifty. Massive evacuation efforts were made once it became clear where Hurricane Andrew would strike the Florida coast, and no doubt many lives were saved as a result. Evacuating a large city in the path of a hurricane, however, can prove more problematic, as the situation in New Orleans proved with Hurricane Katrina.

In countries where the governmental infrastructure is less well developed than in the United States, the kinds of policies followed in the United States will not particularly help. A cyclone that hit Bangladesh in 1991 killed 131,000 people. A typhoon that landed in Vietnam in November 1997 killed 1,100. A cyclone in the Indian state of Andhra Pradesh in November 1996 caused the deaths of more than 1,000 people, and when a cyclone hit the Indian state of Gujarat in June 1998, more than 1,300 people lost their lives. Hurricane Mitch, which hit Central America in late October 1998, killed more than 11,000 and totally devastated the economies of Honduras and Guatemala. Experts have estimated that in Asia alone, the number of people at risk for death from cyclones is somewhere between 12,000 and 23,000.

Although actions taken by society have succeeded, at least in the United States, in reducing the effects of hurricanes on humans, the costs of hurricanes have risen dramatically. Hurricane Camille, which struck the Gulf Coast in 1969, and Hurricane Betsy, which landed in the Bahamas, South Florida, and Louisiana in 1965, produced damages estimated to run in the neighborhood of $1 to $2 billion.

In contrast, the damage caused by Hurricane Andrew, in 1992, totaled more than $25 billion. The largest part of this consisted of damage to private property, but many public structures and roads were also affected. The damage caused by Andrew bankrupted a number of insurance companies, and many more restricted the amount of coverage they would provide in hurricane-prone regions. Hurricane Katrina left widespread damage totaling over $100 billion. As the value and number of properties in coastal areas grow, the risk of major economic dislocation from future hurricanes grows as well. Although some governments have attempted to restrict development along hurricane-prone shores, this approach has proved unpopular and has not been highly successful. Most experts agree that future disasters caused by hurricanes are inevitable.

The year 2017 proved to be a particularly devastating year for hurricanes in North America. The extent of damage caused by Hurricane Harvey, which made landfall as a Category 4 hurricane in Texas on August 25, 2017, was estimated at $125 billion—one of the costliest in US history. As Hurricane Harvey proved to be one of the slowest-moving storms in Texas history, making its way toward Louisiana over a period of five days, southeastern Texas was drenched in an especially extreme amount of rain, eventually amounting to more than twenty trillion gallons over both states; the greatest amount of devastation was experienced in the city of Houston. By mid-September, more than seventy deaths had been attributed to the hurricane. Only days later, beginning on September 6, Hurricane Irma, a Category 5 storm described as one of the strongest hurricanes in history, began making landfall in the northern Caribbean. Hurricane Irma first hit Florida, in the region of the Florida Keys, as a Category 4 storm on the morning of September 10. Throughout the day, it would make a second landfall as a Category 3 storm before moving northward into the central part of the state as a Category 1 hurricane by the following day. Yet another Category 5 Atlantic hurricane (Maria) struck on September 20, this time hitting the island of Puerto Rico, causing widespread devastation that included the destruction of most of the territory's infrastructure. Because US relief efforts were slow to reach the island, many leveled criticism at the administration of President Donald Trump.

In 2018, Hurricane Michael rapidly intensified from a Category 1 storm on October 8 to Category 4 on October 10 before hitting the Florida Panhandle. It produced up to 14 feet of storm surge in the Mexico Beach to Indian Pass area. Michael was notable for coming late in the season, for making landfall in the Panhandle, and for being the strongest hurricane in recorded history to have hit that region. Hurricane Dorian ravaged the Bahamas in September 2019, making landfall as one of the most powerful hurricanes in history with sustained winds of 185 miles per hour. This spate of particularly severe hurricanes in the late 2010s led many to reopen discussion around the environmental effects of climate change and about how to mitigate those effects on coastal regions.

Hurricanes continued to cause devastation in North America into the 2020s. According to the Environmental Protection Agency (EPA), hurricanes originating in the Atlantic increased in frequency, intensity, and duration between 2018 and 2022—a trend that the EPA predicted would continue. Three Category 4 hurricanes made landfall in the US, each with 150 mile per hour winds, between 2020 and 2022: Hurricane Laura, which hit west of New Orleans in 2020; Hurricane Ida, which hit just east of New Orleans in 2021; and Hurricane Ian, which hit near Fort Myers, Florida, in 2022. The latter storm resulted in vast devastation to parts of southwestern and central Florida, including upwards of $75 billion in damage and the lives of at least 119 people.

Despite the severity of twenty-first-century hurricane seasons and the fact that hurricane damage costs continue to rise, the lack of definitive records from before the advent of aircraft and satellite data collection makes determinations about the increasing frequency of hurricanes difficult. However, scientific data do indicate global warming is intensifying hurricanes by increasing evaporation from warmer ocean waters and by increasing their wind speeds as the air pressure gradients increase. Thus, hurricanes will likely produce greater precipitation and storm surges when they make landfall.

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