256-499: Effects Other wikis Hurricane Andrew was a compact, but very powerful and devastating tropical cyclone that struck the Bahamas , Florida, and Louisiana in August ;1992. It was the most destructive hurricane to ever hit Florida in terms of structures damaged or destroyed, and remained the costliest in financial terms until Hurricane Irma surpassed it 25 years later . Andrew
512-685: A Royal Navy Type 42 destroyer , was the operational guard ship at the time and assisted in relief operations in and around the Gregorytown area. In addition, assistance came from Canada, Japan, and the United States, as well as the United Nations . The American Red Cross delivered 100 tents, 100 rolls of plastic sheeting, and 1,000 cots. Rebuilding began quickly on the hardest hit islands. However, trees and vegetation were expected to take years to recover. Despite reconstruction efforts and
768-518: A Tropical Cyclone Warning Centre by the World Meteorological Organization 's (WMO) tropical cyclone programme. These warning centers issue advisories which provide basic information and cover a systems present, forecast position, movement and intensity, in their designated areas of responsibility. Meteorological services around the world are generally responsible for issuing warnings for their own country. There are exceptions, as
1024-431: A low-pressure center, a closed low-level atmospheric circulation , strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls . Depending on its location and strength, a tropical cyclone is called a hurricane ( / ˈ h ʌr ɪ k ən , - k eɪ n / ), typhoon ( / t aɪ ˈ f uː n / ), tropical storm , cyclonic storm , tropical depression , or simply cyclone . A hurricane
1280-488: A "dry season" (winter) which runs from November through April, and a "wet season" (summer) which runs from May through October. About 70% of the annual rainfall in south Florida occurs in the wet season – often as brief but intense tropical downpours. The dry season sees little rainfall and dew points and humidity are often quite low. The dry season can be severe at times, as wildfires and water restrictions are often in place. The annual range of temperatures in south Florida and
1536-416: A 1.5 degree warming lead to "increased proportion of and peak wind speeds of intense tropical cyclones". We can say with medium confidence that regional impacts of further warming include more intense tropical cyclones and/or extratropical storms. Climate change can affect tropical cyclones in a variety of ways: an intensification of rainfall and wind speed, a decrease in overall frequency, an increase in
1792-607: A 13-minute wind speed of 114 mph (183 km/h) was reported. Tropical storm force winds reached as far north as West Palm Beach . On the west coast of Florida, sustained winds remained just below tropical storm force on Marco Island , though a wind gust of 100 mph (160 km/h) was reported in Collier County. Rainfall was generally light, possibly as a result of the storm's relatively fast movement. Overall, precipitation from Andrew peaked at nearly 14 in (360 mm) in western Dade County. Heavy rainfall in other areas
2048-698: A 16.5% error. Several other anemometers measuring the highest wind speeds on land were destroyed or failed. At the National Hurricane Center building in Coral Gables , sustained winds of 115 mph (185 km/h) and gusts to 164 mph (264 km/h) were measured before the anemometer failed. The highest sustained wind speed for the storm was 146 mph (235 km/h), recorded at the Turkey Point Nuclear Generating Station , before instruments also failed there. In Key Largo,
2304-444: A 2019 review paper show a future increase of rainfall rates. Additional sea level rise will increase storm surge levels. It is plausible that extreme wind waves see an increase as a consequence of changes in tropical cyclones, further exacerbating storm surge dangers to coastal communities. The compounding effects from floods, storm surge, and terrestrial flooding (rivers) are projected to increase due to global warming . There
2560-613: A 24‑hour period the atmospheric pressure dropped by 47 mbar (1.388 inHg) to a minimum of 922 mbar (27.23 inHg). On August 23, the storm attained Category 5 status on the Saffir–Simpson hurricane scale , reaching peak winds of 175 mph (282 km/h) a short distance off Eleuthera island in The Bahamas at 18:00 UTC. Despite its intensity, Andrew was a small tropical cyclone, with winds of 35 mph (56 km/h) extending out only about 90 mi (140 km) from
2816-580: A barometric pressure of 922 hPa (27.23 inHg) at the time of landfall in Florida, Andrew is the sixth most-intense hurricane to strike the United States. Several hours later, the hurricane emerged over the Gulf of Mexico at Category 4 strength, with the Gulf Coast of the United States in its dangerous path. After turning northwestward and weakening further, Andrew moved ashore near Morgan City, Louisiana , as
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#17328587042923072-590: A circle, whirling round their central clear eye , with their surface winds blowing counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere . The opposite direction of circulation is due to the Coriolis effect . Tropical cyclones tend to develop during the summer, but have been noted in nearly every month in most tropical cyclone basins . Tropical cyclones on either side of
3328-445: A concern over how Ingraham would handle the hurricane, due to many of the government officials remaining in power from the previous administration; however, government response to the hurricane was normal. Initially, forecasters predicted tides up to 14 ft (4.3 m) above normal along the east coast of Florida, near the potential location of landfall. Rainfall was projected to be between 5 and 8 in (130 and 200 mm) along
3584-622: A decline in tourism by up to 20% in the months after the storm. After assessing the devastation in Florida and Louisiana, U.S. President George H. W. Bush initially proposed a $ 7.1 billion aid package to provide disaster benefits, small-business loans, agricultural recovery, food stamps , and public housing for victims of Hurricane Andrew. After the House of Representatives appropriated aid to victims of Hurricane Iniki in Hawaii and Typhoon Omar in Guam ,
3840-560: A few symptoms of PTSD. Within six months, the circumstances related to the aftermath of Andrew led to at least five suicides and four homicides . As homes were being rebuilt, FEMA provided free temporary mobile homes for 3,501 families and financial assistance to more than 40,000 other families for staying in hotel rooms, paying rent, and repairing homes. Nearly two years after Andrew, about 70% of homes in Homestead that were damaged or destroyed were repaired or rebuilt. Additionally, of
4096-405: A flow of warm, moist, rapidly rising air, which starts to rotate cyclonically as it interacts with the rotation of the earth. Several factors are required for these thunderstorms to develop further, including sea surface temperatures of around 27 °C (81 °F) and low vertical wind shear surrounding the system, atmospheric instability, high humidity in the lower to middle levels of
4352-491: A hardwood hammock as larger trees overtake the slash pines. The understory shrubs in pine rocklands are the fire-resistant saw palmetto ( Serenoa repens ), cabbage palm ( Sabal palmetto ), and West Indian lilac ( Tetrazygia bicolor ). The most diverse group of plants in the pine community are the herbs, of which there are two dozen species. These plants contain tubers and other mechanisms that allow them to sprout quickly after being charred. Prior to urban development of
4608-506: A higher intensity. Most tropical cyclones that experience rapid intensification are traversing regions of high ocean heat content rather than lower values. High ocean heat content values can help to offset the oceanic cooling caused by the passage of a tropical cyclone, limiting the effect this cooling has on the storm. Faster-moving systems are able to intensify to higher intensities with lower ocean heat content values. Slower-moving systems require higher values of ocean heat content to achieve
4864-488: A hurricane warning was issued for the central Bahamas, including Cat Island , Exuma , San Salvador Island , and Long Island . All watches and warnings were discontinued on August 24. The advance warning was credited for the low death toll in the country. A total of 58 shelters were opened at churches, government buildings, and schools. Prime Minister of the Bahamas Hubert Ingraham , who took office while
5120-528: A large airport 6 miles (10 km) north of Everglades National Park was blocked when an environmental study found that it would severely damage the South Florida ecosystem. With heightened awareness and appreciation of the region, restoration began in the 1980s with the removal of a canal that had straightened the Kissimmee River. However, development and sustainability concerns have remained pertinent in
5376-460: A large number of forecasting centers, uses infrared geostationary satellite imagery and an algorithm based upon the Dvorak technique to assess the intensity of tropical cyclones. The ADT has a number of differences from the conventional Dvorak technique, including changes to intensity constraint rules and the usage of microwave imagery to base a system's intensity upon its internal structure, which prevents
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#17328587042925632-464: A large role in both the classification of a tropical cyclone and the determination of its intensity. Used in warning centers, the method was developed by Vernon Dvorak in the 1970s, and uses both visible and infrared satellite imagery in the assessment of tropical cyclone intensity. The Dvorak technique uses a scale of "T-numbers", scaling in increments of 0.5 from T1.0 to T8.0. Each T-number has an intensity assigned to it, with larger T-numbers indicating
5888-460: A low-end Category 3 storm. The small hurricane curved northeastward after landfall and rapidly lost its intensity, becoming extratropical on August 28, and merging with the remnants of Hurricane Lester and a frontal system over the southern Appalachian Mountains on August 29. Andrew first inflicted structural damage as it moved through The Bahamas, especially in Cat Cays , lashing
6144-460: A massive wetland ecosystem. Although the region appears flat, weathering of the limestone created slight valleys and plateaus in some areas. These plateaus rise and fall only a few inches, but on the subtle South Florida topography these small variations affect both the flow of water and the types of vegetation that can take hold. The underlying bedrock or limestone of the Everglades basin affects
6400-582: A minor degree. Property damage alone in St. Mary Parish reached approximately $ 150 million. Iberia Parish was also among the most severely impacted parishes. Two schools collectively sheltering about 3,600 people in Jeanerette and New Iberia lost their roofs. One death occurred in the parish due to electrocution. A total of 407 residences were demolished, 2,528 others were extensively damaged, and 3,526 others were inflicted with minor damage. Overall,
6656-638: A month prior to Andrew, the House Committee on Appropriations – which oversees the budget for FEMA – released a report calling the agency a "political dumping ground" and a "turkey farm" due to its "weak, inexperienced leaders". Congressman S. William Green of New York , a member of the Appropriations Committee, stated that he believed the agency learned little from its botched response to Hurricane Hugo in 1989. However, Green also criticized local officials for expecting "them [FEMA] to come and run
6912-426: A much smaller area. This replenishing of moisture-bearing air after rain may cause multi-hour or multi-day extremely heavy rain up to 40 km (25 mi) from the coastline, far beyond the amount of water that the local atmosphere holds at any one time. This in turn can lead to river flooding , overland flooding, and a general overwhelming of local water control structures across a large area. A tropical cyclone
7168-539: A narrow, deep channel characteristic of most rivers. The vertical gradient from Lake Okeechobee to Florida Bay is about 2 inches (5.1 cm) per mile, creating an almost 60-mile (97 km) wide expanse of river that travels about half a mile (0.8 km) a day. This slow movement of a broad, shallow river is known as sheetflow , and gives the Everglades its nickname, River of Grass. Water leaving Lake Okeechobee may require months or years to reach its final destination, Florida Bay. The sheetflow travels so slowly that water
7424-493: A number of techniques considered to try to artificially modify tropical cyclones. These techniques have included using nuclear weapons , cooling the ocean with icebergs, blowing the storm away from land with giant fans, and seeding selected storms with dry ice or silver iodide . These techniques, however, fail to appreciate the duration, intensity, power or size of tropical cyclones. A variety of methods or techniques, including surface, satellite, and aerial, are used to assess
7680-505: A part in the disappearance of pine forests in the area, as natural fires were put out and pine rocklands transitioned into hardwood hammocks. Prescribed fires occur in Everglades National Park in pine rocklands every three to seven years. Cypress swamps can be found throughout the Everglades, but the largest covers most of Collier County . The Big Cypress Swamp is located to the west of the sawgrass prairies and sloughs, and it
7936-422: A process known as rapid intensification, a period in which the maximum sustained winds of a tropical cyclone increase by 30 kn (56 km/h; 35 mph) or more within 24 hours. Similarly, rapid deepening in tropical cyclones is defined as a minimum sea surface pressure decrease of 1.75 hPa (0.052 inHg) per hour or 42 hPa (1.2 inHg) within a 24-hour period; explosive deepening occurs when
Hurricane Andrew - Misplaced Pages Continue
8192-845: A production loss of 240,000 to 270,000 barrels per day occurred – approximately one-third of production throughout the Gulf of Mexico. Overall, Hurricane Andrew caused about $ 500 million in damage to oil facilities. As Andrew moved ashore in Louisiana, its outer fringes produced a storm tide of about 1.3 ft (0.40 m) in Sabine Pass, Texas . Winds were generally light in the state, reaching 30 mph (48 km/h) in Port Arthur . As Andrew crossed into Mississippi, 3 severe thunderstorm warnings , 21 tornado warnings , and 16 flood warnings were issued. Funnel clouds were observed near
8448-731: A recreational vehicle and its trailer, downed trees, and flattened cornfields. Precipitation continued along the path of Andrew's remnants through the Mid-Atlantic and Ohio Valley, with precipitation measured as far north as Upstate New York . Initially, the Bahamas National Disaster Coordinator believed that foreign aid was not required, but shortly after the storm, the Government of the United Kingdom began distributing blankets, food, ice, and water. HMS Cardiff ,
8704-429: A remnant low-pressure area . Remnant systems may persist for several days before losing their identity. This dissipation mechanism is most common in the eastern North Pacific. Weakening or dissipation can also occur if a storm experiences vertical wind shear which causes the convection and heat engine to move away from the center. This normally ceases the development of a tropical cyclone. In addition, its interaction with
8960-654: A rise in elevation along the eastern coast of Florida, called the Eastern Coastal Ridge, that was formed as waves compressed ooids into a single formation. Along the western border of the Big Cypress Swamp is the Immokolee Ridge (or Immokolee Rise), a slight rise of compressed sand that divides the runoff between the Caloosahatchee River and The Big Cypress. This slight rise in elevation on both sides of
9216-501: A shelter in the former. Gambling ships were moved into harbors and inland canals. Two run-offs for special legislative elections scheduled for August 25 were postponed. In Louisiana , Governor Edwin Edwards declared a state of emergency. About 1.25 million people evacuated from the central and southeast Louisiana, while approximately 60,000 others fled parishes in southwest Louisiana. A mandatory evacuation from Grand Isle
9472-468: A single grain of sand or shell fragment. The other facies, which underlies the eastern lower Everglades (in Miami-Dade County and part of Monroe County) consists of fossilized bryozoan organisms. The unique structure was some of the first material used in housing in early 20th-century South Florida. The composition of this sedimentary formation affects the hydrology, plant life, and wildlife above it:
9728-485: A slightly lower pressure of 922 mbar (27.23 inHg). This barometric pressure made Andrew the most intense hurricane to strike the United States since Hurricane Camille in 1969 and the strongest tropical cyclone to make landfall in Florida since the Labor Day hurricane of 1935 . The United States would not experience another landfall from a hurricane at Category 5 intensity until Hurricane Michael in 2018 . As
9984-562: A storm. Tropical cyclone scales , such as the Saffir-Simpson hurricane wind scale and Australia's scale (Bureau of Meteorology), only use wind speed for determining the category of a storm. The most intense storm on record is Typhoon Tip in the northwestern Pacific Ocean in 1979, which reached a minimum pressure of 870 hPa (26 inHg ) and maximum sustained wind speeds of 165 kn (85 m/s; 305 km/h; 190 mph). The highest maximum sustained wind speed ever recorded
10240-565: A stronger system. Tropical cyclones are assessed by forecasters according to an array of patterns, including curved banding features , shear, central dense overcast, and eye, to determine the T-number and thus assess the intensity of the storm. The Cooperative Institute for Meteorological Satellite Studies works to develop and improve automated satellite methods, such as the Advanced Dvorak Technique (ADT) and SATCON. The ADT, used by
10496-405: A system has dissipated or lost its tropical characteristics, its remnants could regenerate a tropical cyclone if environmental conditions become favorable. A tropical cyclone can dissipate when it moves over waters significantly cooler than 26.5 °C (79.7 °F). This will deprive the storm of such tropical characteristics as a warm core with thunderstorms near the center, so that it becomes
Hurricane Andrew - Misplaced Pages Continue
10752-511: A three-year reserve fund for losses to uninsured businesses, homes, government, and school buildings and functions. The bill allowed South Floridians to keep an estimated $ 500 million in sales tax generated by rebuilding efforts. Crime, especially looting and theft, rose sharply in the areas south of Miami immediately after Andrew. Reports indicate that merchandise was stolen at damaged or destroyed shopping centers in southern Dade County, and looting occurred in neighborhoods severely affected by
11008-518: A tropical cyclone are a result of the conservation of angular momentum imparted by the Earth's rotation as air flows inwards toward the axis of rotation. As a result, cyclones rarely form within 5° of the equator . Tropical cyclones are very rare in the South Atlantic (although occasional examples do occur ) due to consistently strong wind shear and a weak Intertropical Convergence Zone . In contrast,
11264-461: A tropical cyclone's core has a negative effect on its development and intensity by diminishing atmospheric convection and introducing asymmetries in the storm's structure. Symmetric, strong outflow leads to a faster rate of intensification than observed in other systems by mitigating local wind shear. Weakening outflow is associated with the weakening of rainbands within a tropical cyclone. Tropical cyclones may still intensify, even rapidly, in
11520-401: A tropical cyclone's intensity or the direction it is traveling. Wind-pressure relationships (WPRs) are used as a way to determine the pressure of a storm based on its wind speed. Several different methods and equations have been proposed to calculate WPRs. Tropical cyclones agencies each use their own, fixed WPR, which can result in inaccuracies between agencies that are issuing estimates on
11776-560: A two-digit number and suffix letter by the warning centers that monitor them. Everglades The Everglades is a natural region of flooded grasslands in the southern portion of the U.S. state of Florida , comprising the southern half of a large drainage basin within the Neotropical realm . The system begins near Orlando with the Kissimmee River , which discharges into the vast but shallow Lake Okeechobee . Water leaving
12032-813: A typhoon. This happened in 2014 for Hurricane Genevieve , which became Typhoon Genevieve. Within the Southern Hemisphere, it is either called a hurricane, tropical cyclone or a severe tropical cyclone, depending on if it is located within the South Atlantic, South-West Indian Ocean, Australian region or the South Pacific Ocean. The descriptors for tropical cyclones with wind speeds below 65 kn (120 km/h; 75 mph) vary by tropical cyclone basin and may be further subdivided into categories such as "tropical storm", "cyclonic storm", "tropical depression", or "deep depression". The practice of using given names to identify tropical cyclones dates back to
12288-509: A vigorous circulation aloft. After the upper-level low weakened and split into a trough , the wind shear decreased over the storm. A strong high pressure system then developed over the southeastern United States, which built eastward and caused Andrew to turn to the west. Convection became more organized as upper-level outflow became better established. An eye formed, and Andrew attained hurricane status early on August 22, about 650 mi (1,050 km) east-southeast of Nassau, Bahamas . In
12544-428: A week without significantly strengthening itself in the central Atlantic, the storm rapidly intensified into a powerful Category 5 hurricane while moving westward towards The Bahamas on August 23. Though Andrew briefly weakened to Category 4 status while traversing The Bahamas, it regained Category 5 intensity before making landfall in Florida on Elliott Key and then Homestead on August 24. With
12800-664: A wetter landscape; large animals became extinct in Florida, and the Paleo-Indians slowly adapted and became the Archaic peoples . They conformed to the environmental changes, and created many tools with the various resources available. During the Late Archaic period, the climate became wetter again, and approximately 3000 BCE the rise of water tables allowed an increase in population and cultural activity. Florida Indians developed into three distinct but similar cultures that were named for
13056-554: A wind gust of 41 mph (66 km/h) was observed in Huntsville . Although 48 counties in Alabama reported wind damage, impact across the state was generally minor. Tropical storm force wind gusts and damaging tornadoes extended eastward into Georgia. Several counties in the northwest and west-central portions of the state reported downed trees and tree limbs and fallen power lines, causing scattered power outages, but structural damage
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#173285870429213312-422: A year, and major hurricanes about once every ten years. Between 1871 and 1981, 138 tropical cyclones struck directly over or close to the Everglades. Strong winds from these storms disperse plant seeds and replenish mangrove forests, coral reefs, and other ecosystems. Dramatic fluctuations in precipitation are characteristic of the South Florida climate. Droughts , floods , and tropical cyclones are part of
13568-683: Is a strong tropical cyclone that occurs in the Atlantic Ocean or northeastern Pacific Ocean . A typhoon occurs in the northwestern Pacific Ocean. In the Indian Ocean and South Pacific, comparable storms are referred to as "tropical cyclones". In modern times, on average around 80 to 90 named tropical cyclones form each year around the world, over half of which develop hurricane-force winds of 65 kn (120 km/h; 75 mph) or more. Tropical cyclones typically form over large bodies of relatively warm water. They derive their energy through
13824-415: Is assumed at this stage that a tropical cyclone has become self-sustaining and can continue to intensify without any help from its environment. Depending on its location and strength, a tropical cyclone is referred to by different names , including hurricane , typhoon , tropical storm , cyclonic storm , tropical depression , or simply cyclone . A hurricane is a strong tropical cyclone that occurs in
14080-406: Is calculated as: where p {\textstyle p} is the density of air, u {\textstyle u} is a sustained surface wind speed value, and d v {\textstyle d_{v}} is the volume element . Around the world, tropical cyclones are classified in different ways, based on the location ( tropical cyclone basins ), the structure of
14336-429: Is commonly called "The Big Cypress". The name refers to its area rather than the height or diameter of the trees; at its most conservative estimate, the swamp measures 1,200 square miles (3,100 km ), but the hydrologic boundary of The Big Cypress can be calculated at over 2,400 square miles (6,200 km ). Most of The Big Cypress sits atop a bedrock covered by a thinner layer of limestone. The limestone underneath
14592-545: Is currently no consensus on how climate change will affect the overall frequency of tropical cyclones. A majority of climate models show a decreased frequency in future projections. For instance, a 2020 paper comparing nine high-resolution climate models found robust decreases in frequency in the Southern Indian Ocean and the Southern Hemisphere more generally, while finding mixed signals for Northern Hemisphere tropical cyclones. Observations have shown little change in
14848-422: Is currently the ninth-costliest Atlantic hurricane to hit the United States. It is also the third-strongest hurricane to hit the U.S. mainland by wind speed (165 mph (266 km/h)). Andrew's origins can be traced back to August 14, when a tropical wave moved off the west coast of Africa. A ridge of high pressure to its north caused the wave to move quickly westward. An area of convection developed along
15104-414: Is cut off from its supply of warm moist maritime air and starts to draw in dry continental air. This, combined with the increased friction over land areas, leads to the weakening and dissipation of the tropical cyclone. Over a mountainous terrain, a system can quickly weaken. Over flat areas, it may endure for two to three days before circulation breaks down and dissipates. Over the years, there have been
15360-403: Is fed by the extensive Kissimmee , Caloosahatchee , Miami , Myakka , and Peace Rivers in central Florida. The Kissimmee River is a broad floodplain that empties directly into Lake Okeechobee, which at 730 square miles (1,900 km ) with an average depth of 9 feet (2.7 m), is a vast but shallow lake. Soil deposits in the Everglades basin indicate that peat is deposited where the land
15616-443: Is flooded consistently throughout the year. Calcium deposits are left behind when flooding is shorter. The deposits occur in areas where water rises and falls depending on rainfall, as opposed to water being stored in the rock from one year to the next. Calcium deposits are present where more limestone is exposed. The area from Orlando to the tip of the Florida peninsula was at one point a single drainage unit. When rainfall exceeded
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#173285870429215872-616: Is less likely to erode the limestone to form solution holes —smaller versions of sinkholes that do not intersect with the water table. In this formation the beds are generally impermeable. Underneath the metropolitan areas of Palm Beach County is the Anastasia Formation, composed of shelly limestone, coquina , and sand representing a former mangrove or salt marsh. The Anastasia Formation is much more permeable and filled with pocks and solution holes. The Fort Thompson and Anastasia Formations, and Miami Limestone and (x), were formed during
16128-448: Is more calcitic in composition. Initial attempts at developing agriculture near Lake Okeechobee were successful, but the nutrients in the peat were rapidly removed. In a process called soil subsidence , oxidation of peat causes loss of volume. Bacteria decompose dead sawgrass slowly underwater without oxygen. When the water was drained in the 1920s and bacteria interacted with oxygen, an aerobic reaction occurred. Microorganisms degraded
16384-445: Is the generic term for a warm-cored, non-frontal synoptic-scale low-pressure system over tropical or subtropical waters around the world. The systems generally have a well-defined center which is surrounded by deep atmospheric convection and a closed wind circulation at the surface. A tropical cyclone is generally deemed to have formed once mean surface winds in excess of 35 kn (65 km/h; 40 mph) are observed. It
16640-502: Is the greatest. However, each particular basin has its own seasonal patterns. On a worldwide scale, May is the least active month, while September is the most active month. November is the only month in which all the tropical cyclone basins are in season. In the Northern Atlantic Ocean , a distinct cyclone season occurs from June 1 to November 30, sharply peaking from late August through September. The statistical peak of
16896-405: Is the storm's wind speed and r {\textstyle r} is the radius of hurricane-force winds. The Hurricane Severity Index is a scale that can assign up to 50 points to a system; up to 25 points come from intensity, while the other 25 come from the size of the storm's wind field. The IKE model measures the destructive capability of a tropical cyclone via winds, waves, and surge. It
17152-569: Is typically stored from one wet season to the next in the porous limestone substrate. The ebb and flow of water has shaped the land and every ecosystem in South Florida throughout the Everglades' estimated 5,000 years of existence. The motion of water defines plant communities and how animals adapt to their habitats and food sources. The climate of South Florida is located across the broad transition zone between subtropical and tropical climates ( Koppen Aw , Am and Cfa). Like most regions with this climate type, there are two basic seasons –
17408-608: The African easterly jet and areas of atmospheric instability give rise to cyclones in the Atlantic Ocean and Caribbean Sea . Heat energy from the ocean acts as the accelerator for tropical cyclones. This causes inland regions to suffer far less damage from cyclones than coastal regions, although the impacts of flooding are felt across the board. Coastal damage may be caused by strong winds and rain, high waves (due to winds), storm surges (due to wind and severe pressure changes), and
17664-507: The Atlantic Ocean or northeastern Pacific Ocean , and a typhoon occurs in the northwestern Pacific Ocean. In the Indian Ocean and South Pacific, comparable storms are referred to as "tropical cyclones", and such storms in the Indian Ocean can also be called "severe cyclonic storms". Tropical refers to the geographical origin of these systems, which form almost exclusively over tropical seas. Cyclone refers to their winds moving in
17920-730: The Florida Keys . By 18:00 UTC on August 24, all watches and warnings issued were discontinued after Andrew progressed into the Gulf of Mexico. Governor Lawton Chiles declared a state of emergency and activated about one-third of the Florida National Guard . Many residents evacuated, most voluntarily, from Broward , Charlotte , Collier , Lee , Martin , Dade , Monroe , Palm Beach , and Sarasota counties. A total of 142 shelters opened in these counties and collectively housed at least 84,340 people. In Dade County alone, 515,670 people were ordered to evacuate. As Andrew
18176-547: The Floridan Aquifer , which serves as the main source of fresh water for the northern portion of Florida. However, this aquifer lies beneath thousands of feet of impermeable sedimentary rock from Lake Okeechobee to the southern tip of the peninsula. Five geologic formations form the surface of the southern portion of Florida: the Tamiami Formation , Caloosahatchee Formation , Anastasia Formation , Miami Limestone , and
18432-663: The Fort Thompson Formation . The Tamiami Formation is a compression of highly permeable light-colored fossiliferous sands and pockets of quartz , 150 feet (46 m) thick. It is named for the Tamiami Trail that follows the upper bedrock of the Big Cypress Swamp, and underlies the southern portion of the Everglades. Between the Tamiami Formation and Lake Okeechobee is the Caloosahatchee Formation, named for
18688-618: The Hurricane Surge Index , the Hurricane Severity Index , the Power Dissipation Index (PDI), and integrated kinetic energy (IKE). ACE is a metric of the total energy a system has exerted over its lifespan. ACE is calculated by summing the squares of a cyclone's sustained wind speed, every six hours as long as the system is at or above tropical storm intensity and either tropical or subtropical. The calculation of
18944-582: The Louisiana National Guard patrolled the streets during the storm. The Red Cross assisted with opening a shelter at the University of Southwest Louisiana 's Cajundome in Lafayette , equipped to handle about 2,000 people. In Texas, about 250,000 people evacuated Orange and Jefferson counties. Galveston City Manager Doug Matthews advised residents to develop an evacuation plan in case
19200-559: The Madden–Julian oscillation . The IPCC Sixth Assessment Report summarize the latest scientific findings about the impact of climate change on tropical cyclones. According to the report, we have now better understanding about the impact of climate change on tropical storm than before. Major tropical storms likely became more frequent in the last 40 years. We can say with high confidence that climate change increase rainfall during tropical cyclones. We can say with high confidence that
19456-485: The Pleistocene approximately 17,000 years ago, the runoff of water from Lake Okeechobee slowed and created the vast marshland that is now known as the Everglades. Slower runoff also created an accumulation of almost 18 feet (5.5 m) of peat in the area. The presence of such peat deposits, dated to about 5,000 years ago, is evidence that widespread flooding had occurred by then. The consistent Everglades flooding
19712-404: The Saffir–Simpson scale . Climate oscillations such as El Niño–Southern Oscillation (ENSO) and the Madden–Julian oscillation modulate the timing and frequency of tropical cyclone development. Rossby waves can aid in the formation of a new tropical cyclone by disseminating the energy of an existing, mature storm. Kelvin waves can contribute to tropical cyclone formation by regulating
19968-561: The Saffir–Simpson scale . The trend was most clear in the North Atlantic and in the Southern Indian Ocean. In the North Pacific, tropical cyclones have been moving poleward into colder waters and there was no increase in intensity over this period. With 2 °C (3.6 °F) warming, a greater percentage (+13%) of tropical cyclones are expected to reach Category 4 and 5 strength. A 2019 study indicates that climate change has been driving
20224-689: The Sangamonian interglacial period. The geologic formations that have the most influence on the Everglades are the Miami Limestone and the Fort Thompson Formation. The Miami Limestone has two facies . The Miami Oolite facies, which underlies the Atlantic Coastal Ridge from southern Palm Beach County to southern Miami-Dade County, is made up of ooids : tiny formations of egg-shaped concentric shells and calcium carbonate, formed around
20480-740: The Seminole Tribe of Florida . People who kept more traditional ways had settlements along the Tamiami Trail and tended to speak the Mikasuki language . They later were federally recognized in 1962 as the Miccosukee Tribe of Indians of Florida . As metropolitan areas in South Florida began to grow, the two groups were closely associated with the Everglades. They struggled to maintain privacy while serving as tourist attractions. They earned money by wrestling alligators and selling craftworks. As of 2008 ,
20736-408: The hydroperiod , or how long an area within the region stays flooded throughout the year. Longer hydroperiods are possible in areas that were submerged beneath seawater for longer periods of time, while the geology of Florida was forming. More water is held within the porous ooids and limestone than older types of rock that spent more time above sea level. A hydroperiod of ten months or more fosters
20992-486: The lake in the wet season forms a slow-moving river 60 miles (97 km) wide and over 100 miles (160 km) long, flowing southward across a limestone shelf to Florida Bay at the southern end of the state. The Everglades experiences a wide range of weather patterns, from frequent flooding in the wet season to drought in the dry season. Throughout the 20th century, the Everglades suffered significant loss of habitat and environmental degradation . Human habitation in
21248-551: The royal palms and one-third of the pine trees in the former. In addition to the damage at Everglades National Park, effects in Monroe County were significant, especially in the Upper Florida Keys. Strong winds damaged billboards, awnings, commercial signs, several boats, planes, trees, and 1,500 homes, with 300 of those becoming uninhabitable. Damage in that county was about $ 131 million. In Collier County , to
21504-514: The troposphere , enough Coriolis force to develop a low-pressure center , and a pre-existing low-level focus or disturbance. There is a limit on tropical cyclone intensity which is strongly related to the water temperatures along its path. and upper-level divergence. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide. Of those, 47 reach strength higher than 119 km/h (74 mph), and 20 become intense tropical cyclones, of at least Category 3 intensity on
21760-621: The Atlantic hurricane season is September 10. The Northeast Pacific Ocean has a broader period of activity, but in a similar time frame to the Atlantic. The Northwest Pacific sees tropical cyclones year-round, with a minimum in February and March and a peak in early September. In the North Indian basin, storms are most common from April to December, with peaks in May and November. In the Southern Hemisphere,
22016-557: The Big Cypress contains quartz , which creates sandy soil that hosts a variety of vegetation different from what is found in other areas of the Everglades. The basin for The Big Cypress receives on average 55 inches (140 cm) of water in the wet season. Although The Big Cypress is the largest growth of cypress swamps in South Florida, cypress swamps can be found near the Atlantic Coastal Ridge and between Lake Okeechobee and
22272-449: The Eastern Coastal Ridge receiving the majority of precipitation and the area surrounding Lake Okeechobee receiving about 48 inches (120 cm). Unlike any other wetland system on earth, the Everglades are sustained primarily by the atmosphere. Evapotranspiration – the sum of evaporation and plant transpiration from the Earth's land surface to atmosphere – associated with thunderstorms, is
22528-477: The Eastern flatwoods, as well as in sawgrass marshes. Cypresses are deciduous conifers that are uniquely adapted to thrive in flooded conditions, with buttressed trunks and root projections that protrude out of the water, called "knees". Bald cypress trees grow in formations with the tallest and thickest trunks in the center, rooted in the deepest peat. As the peat thins out, cypresses grow smaller and thinner, giving
22784-539: The Equator generally have their origins in the Intertropical Convergence Zone , where winds blow from either the northeast or southeast. Within this broad area of low-pressure, air is heated over the warm tropical ocean and rises in discrete parcels, which causes thundery showers to form. These showers dissipate quite quickly; however, they can group together into large clusters of thunderstorms. This creates
23040-655: The Everglades creates a basin, and forces water that overflows Lake Okeechobee to creep toward the southwest. Under both the Miami Limestone formation and the Fort Thompson limestone lies the Biscayne Aquifer , a surface aquifer that serves as the Miami metropolitan area 's fresh water source. Rainfall and stored water in the Everglades replenish the Biscayne Aquifer directly. With the rise of sea levels that occurred during
23296-517: The Everglades during the Seminole Wars of the early 19th century. After adapting to the region, they were able to resist removal by the United States Army. Migrants to the region who wanted to develop plantations first proposed draining the Everglades in 1848, but no work of this type was attempted until 1882. Canals were constructed throughout the first half of the 20th century, and spurred
23552-591: The Everglades is rather small (less than 20 °F [11 °C]) – ranging from a monthly mean temperature of around 65 °F (18 °C) in January to 83 °F (28 °C) in July. High temperatures in the hot and wet season (summer) typically exceed 90 °F (32 °C) across inland south Florida (although coastal locations are cooled by winds from the Gulf of Mexico and the Atlantic Ocean), while high temperatures in
23808-466: The Everglades is the sawgrass marsh. The iconic water and sawgrass combination in the shallow river 100 miles (160 km) long and 60 miles (97 km) wide that spans from Lake Okeechobee to Florida Bay is often referred to as the "true Everglades" or just "the Glades". Prior to the first drainage attempts in 1905, the sheetflow occupied nearly a third of the lower Florida peninsula. Sawgrass thrives in
24064-405: The Everglades itself. It is one of the most sparsely populated areas of the state. The geology of South Florida, together with a warm, wet, subtropical/tropical climate, provides conditions well-suited for a large marshland ecosystem. Layers of porous and permeable limestone create water-bearing rock and soil that affect the climate, weather, and hydrology of South Florida. The properties of
24320-493: The Everglades system include the Shark River Slough flowing out to Florida Bay, Lostmans River Slough bordering The Big Cypress, and Taylor Slough in the eastern Everglades. Wet prairies are slightly elevated like sawgrass marshes, but with greater plant diversity. The surface is covered in water only three to seven months of the year, and the water is, on average, shallow at only 4 inches (10 cm) deep. When flooded,
24576-507: The Everglades was on Spanish maps made by cartographers who had not seen the land. They named the unknown area between the Gulf and Atlantic coasts of Florida Laguna del Espíritu Santo ("Lake of the Holy Spirit"). The area was featured on maps for decades without having been explored. Writer James Grant Forbes stated in 1811, "The Indians represent [the Southern points] as impenetrable; and
24832-410: The Everglades watershed system. Evapotranspiration is responsible for approximately 70–90 percent of water entering undeveloped wetland regions in the Everglades. Precipitation during the wet season is primarily caused by air mass thunderstorms and the easterly flow out of the subtropical high (Bermuda High). Intense daytime heating of the ground causes the warm moist tropical air to rise, creating
25088-679: The Everglades, but rarely lived in them. Canoe trips to Cuba were also common. Estimated numbers of Calusa at the beginning of the Spanish occupation ranged from 4,000 to 7,000. The society declined in power and population; by 1697 their number was estimated to be about 1,000. In the early 18th century, the Calusa came under attack from the Yamasee to the north. They asked the Spanish for refuge in Cuba, where almost 200 died of illness. Soon they were relocated again to
25344-496: The Everglades. Much of the coast and the inner estuaries are built of mangroves; there is no border between the coastal marshes and the bay. Thus the marine ecosystems in Florida Bay are considered to be a part of the Everglades watershed and one of the ecosystems connected to and affected by the Everglades as a whole. More than 800 square miles (2,100 km ) of Florida Bay is protected by Everglades National Park , representing
25600-789: The Florida Keys. Second in power and number to the Calusa in South Florida were the Tequesta . They occupied the southeastern portion of the lower peninsula in modern-day Dade and Broward counties. Like the Calusa, the Tequesta societies centered on the mouths of rivers. Their main village was probably on the Miami River or Little River. Spanish depictions of the Tequesta state that they were greatly feared by sailors, who suspected them of torturing and killing survivors of shipwrecks. With an increasing European presence in south Florida, Native Americans from
25856-635: The Gulf Coast were discontinued late on August 26 after the hurricane moved inland over Louisiana. Due to the hurricane's threat, workers fled oil platforms in the Gulf of Mexico, while the Coast Guard moved their boats inland. Officials in Mississippi suggested that about 100,000 people evacuate the coastal counties . Shelters were opened in Hancock and Harrison counties, though only 68 people went to
26112-500: The Gulf of Mexico , leading to $ 500 million in losses for oil companies. It produced hurricane-force winds along its path through Louisiana, damaging large stretches of power lines that left about 230,000 people without electricity. Over 80% of trees in the Atchafalaya River basin were downed, and the agriculture there was devastated. Throughout the basin and Bayou Lafourche , 187 million freshwater fish were killed in
26368-481: The Gulf of Mexico and made landfall about 23 mi (37 km) west-southwest of Morgan City in south-central Louisiana; at landfall, the maximum sustained winds were 115 mph (185 km/h). The highest sustained wind speed observed was 96 mph (154 km/h), while a wind gust as strong as 120 mph (190 km/h) was recorded; both measurements were taken at the fire station in Berwick . As it moved ashore,
26624-548: The Haag Engineer Company in Carrollton , Texas, highlighted construction issues in homes. Concrete tiles were glued to felt paper, while shingles were stapled perpendicular to the long axis, allowing them to be torn away. This exposed plywood and prefabricated trusses to weather, leading to structural failure and roof collapses. Tropical cyclone A tropical cyclone is a rapidly rotating storm system with
26880-492: The Keys and other areas began increasing their trips to Cuba. Official permission for the immigration of Native Americans from the Florida Keys was granted by Cuban officials in 1704. Spanish priests attempted to set up missions in 1743, but noted that the Tequesta were under assault from a neighboring tribe. When only 30 members were left, they were removed to Havana. A British surveyor in 1770 described multiple deserted villages in
27136-629: The PDI is similar in nature to ACE, with the major difference being that wind speeds are cubed rather than squared. The Hurricane Surge Index is a metric of the potential damage a storm may inflict via storm surge. It is calculated by squaring the dividend of the storm's wind speed and a climatological value (33 m/s or 74 mph), and then multiplying that quantity by the dividend of the radius of hurricane-force winds and its climatological value (96.6 km or 60.0 mi). This can be represented in equation form as: where v {\textstyle v}
27392-613: The Red Cross placed their disaster alert teams on standby and ready to respond if the hurricane threatened the Corpus Christi area . Even though Andrew was a small tropical cyclone for most of its lifespan, it caused extreme damage, especially in the Bahamas, Florida, and Louisiana. The vast majority of the damage was as a result of extremely high winds, although a few tornadoes spawned by Andrew caused considerable damage in Louisiana. Throughout
27648-541: The Seminole Tribe of Florida had five reservations, and the lands of the Miccosukee Tribe of Indians were collectively considered a sixth reservation. The two tribes have each developed casino gaming on some of their properties to generate revenue for support, services and economic development. The military penetration of southern Florida offered the opportunity to map a poorly understood and largely unknown part of
27904-481: The Seminole in the Everglades numbered no more than 325. They made a living by hunting and trading with white settlers, and raised domesticated animals. The Seminole made their villages in hardwood hammocks or pinelands, had diets of hominy and coontie roots, fish, turtles, venison, and small game. Their villages were not large, due to the limited size of the hammocks. Between the end of the last Seminole War and 1930,
28160-548: The Seminole, and became known as the Black Seminoles . The groups acted as allies. In 1817, Andrew Jackson invaded Florida to hasten its annexation to the United States, in what became known as the First Seminole War . After Florida became a U.S. territory in 1821, conflicts between settlers and the Seminole increased as the former tried to acquire lands. The Second Seminole War lasted from 1835 to 1842, and afterward,
28416-460: The South Atlantic is not a major basin, and not an official basin according to the WMO. Each year on average, around 80 to 90 named tropical cyclones form around the world, of which over half develop hurricane-force winds of 65 kn (120 km/h; 75 mph) or more. Worldwide, tropical cyclone activity peaks in late summer, when the difference between temperatures aloft and sea surface temperatures
28672-464: The South Florida economy, prompting land development. In 1947, Congress formed the Central and Southern Florida Flood Control Project , which built 1,400 miles (2,300 km) of canals, levees , and water control devices. The Miami metropolitan area grew substantially at this time and Everglades water was diverted to cities. Portions of the Everglades were transformed into farmland, where the primary crop
28928-460: The South Florida region, pine rocklands covered approximately 161,660 acres (654.2 km ) in Miami-Dade County . Within Everglades National Park, 19,840 acres (80.3 km ) of pine forests are protected, but outside the park, 1,780 acres (7.2 km ) of pine communities remained as of 1990, averaging 12.1 acres (49,000 m ) in area. The misunderstanding of the role of fire also played
29184-624: The US forcibly removed about 3,000 Seminole and 800 Black Seminole to Indian Territory (now Oklahoma), west of the Mississippi River. Many others died in the war. Conflict broke out again in the Third Seminole War from 1855 to 1859, when a few hundred Seminole fought off US forces from the swamps of the Everglades. The US finally decided to leave them alone, as they could not dislodge them even after this protracted and expensive warfare. By 1913,
29440-585: The United States National Hurricane Center and Fiji Meteorological Service issue alerts, watches and warnings for various island nations in their areas of responsibility. The United States Joint Typhoon Warning Center and Fleet Weather Center also publicly issue warnings about tropical cyclones on behalf of the United States Government . The Brazilian Navy Hydrographic Center names South Atlantic tropical cyclones , however
29696-575: The Western Pacific. Tropical cyclones have to have a significant amount of gale-force winds occurring around the center before they are named within the Southern Hemisphere . The names of significant tropical cyclones in the North Atlantic Ocean, Pacific Ocean, and Australian region are retired from the naming lists and replaced with another name. Tropical cyclones that develop around the world are assigned an identification code consisting of
29952-449: The [British] surveyors, wreckers, and coasters, had not the means of exploring beyond the borders of the sea coast, and the mouths of rivers". British surveyor John Gerard de Brahm , who mapped the coast of Florida in 1773, called the area "River Glades". The name "Everglades" first appeared on a map in 1823, although it was also spelled as "Ever Glades" as late as 1851. The Seminole call it Pahokee , meaning "Grassy Water". The region
30208-472: The afternoon thundershowers typical of tropical climates. 2:00 pm is the mean time of daily thundershowers across South Florida and the Everglades. Late in the wet season (August and September), precipitation levels reach their highest levels as tropical depressions and lows add to daily rainfall. Occasionally, tropical lows can become severe tropical cyclones and cause significant damage when they make landfall across south Florida. Tropical storms average one
30464-657: The algae formations and microscopic plankton. Female sea turtles return annually to nest on the shore, and manatees spend the winter months in the warmer water of the bay. Sea grasses also serve to stabilize the sea beds and protect shorelines from erosion by absorbing energy from waves. Humans arrived in the Florida peninsula approximately 15,000 years ago. Paleo-Indians came to Florida probably following large game that included giant sloths , saber-toothed cats , and spectacled bears . They found an arid landscape that supported plants and animals adapted for desert conditions. However, 6,500 years ago, climate changes brought
30720-647: The area were estimated to have ranged from 130 to 150 mph (210 to 240 km/h), slightly below the threshold for an F3 tornado. Four of the five condominiums at Naranja Lakes were destroyed. The Cutler Ridge Mall suffered severe wind and water damage; after the storm, significant looting was reported at that location. More than 50 streets were blocked by fallen trees and power lines. Agriculture suffered extensively as well, with an 85% loss to fruit crops such as avocados, limes, and mangoes. Crop damage in Dade County totaled about $ 509 million. The county suffered
30976-954: The areas affected, almost 177,000 people were left homeless. Outside of The Bahamas, Florida, and Louisiana, effects were widespread, although damage was minimal. Overall, $ 27.3 billion in losses and 65 fatalities were attributed to Andrew, although many other estimates range as high as $ 36 billion. Andrew was the costliest hurricane in U.S. history at the time, but is now ninth following hurricanes Katrina (2005), Ike (2008), Sandy (2012), Harvey (2017), Irma (2017), Maria (2017), Ida (2021), and Ian (2022). Hurricane Andrew brought maximum sustained winds of over 119 km/h (74 mph) to five districts – North Eleuthera , New Providence , North Andros , Bimini , Berry Islands – as well as three cays . The storm first struck North Eleuthera, The hurricane also produced tropical storm force winds in seven districts, including Cat Island , South Abaco , Central Andros ,
31232-472: The base were severely damaged or rendered unusable. Damage to the base was extensive enough that it was recommended for closure. Nearby, in the small town of Florida City , over 120 homes were demolished and 700 others were damaged, while a number of other buildings were damaged beyond repair, including City Hall. Further north, damage to poorly constructed homes in communities such as Country Walk and Saga Bay resembled that of an F3 tornado . Winds in
31488-463: The bodies of water near where they were located: Okeechobee , Caloosahatchee , and Glades . From the Glades peoples, two major nations emerged in the area: the Calusa and the Tequesta . The Calusa was the largest and most powerful nation in South Florida. It controlled fifty villages located on Florida's west coast, around Lake Okeechobee, and on the Florida Keys . Most Calusa villages were located at
31744-587: The calcitic composition of the marl. Sloughs , or free-flowing channels of water, develop in between sawgrass prairies. Sloughs are about 3 feet (0.91 m) deeper than sawgrass marshes, and may stay flooded for at least 11 months out of the year and sometimes multiple years in a row. Aquatic animals such as turtles, alligators, snakes, and fish thrive in sloughs; they usually feed on aquatic invertebrates. Submerged and floating plants grow here, such as bladderwort ( Utricularia ), waterlily ( Nymphaeaceae ), and spatterdock ( Nuphar lutea ). Major sloughs in
32000-422: The capacity of Lake Okeechobee and the Kissimmee River floodplain, it spilled over and flowed in a southwestern direction to empty into Florida Bay . Prior to urban and agricultural development in Florida, the Everglades began at the southern edge of Lake Okeechobee and flowed for approximately 100 miles (160 km), emptying into the Gulf of Mexico. The limestone shelf is wide and slightly angled instead of having
32256-524: The center. After reaching that intensity, the hurricane underwent an eyewall replacement cycle . At 21:00 UTC on August 23, Andrew made landfall on Eleuthera as a Category 5 hurricane, with winds of 160 mph (260 km/h). The cyclone weakened further while crossing the Bahama Banks , and at 01:00 UTC on August 24, Andrew hit the southern Berry Islands of The Bahamas as a Category 4 hurricane, with winds of 150 mph (240 km/h). As it crossed over
32512-678: The city chose to call for evacuations. The city later decided against ordering an evacuation. School was canceled on August 25 for Beaumont , Port Arthur , and other areas of central Jefferson County, while schools were closed in Dickinson , High Island , Hitchcock , La Marque , Santa Fe , and Texas City on August 26. College of the Mainland , Galveston College , and Texas A&M University at Galveston were also closed. Emergency management crews in Corpus Christi began testing emergency generators and severe weather gear. The Comal County chapter of
32768-432: The compactness of the hurricane, although it caused between $ 96 million and more than $ 500 million in losses to boats and buildings, based on various sources. At the height of the storm, more than 1.4 million people lost electricity and another 150,000 were without telephone service. It is estimated that throughout Florida, the storm damaged 101,241 homes and destroyed approximately 63,000 others –
33024-458: The cost was later increased to $ 11.1 billion. The bill, which was the most costly disaster aid package at the time, was passed by Congress as House Resolution 5620 on September 18, and signed into law by President Bush on September 23. The state of Florida alone received $ 9 billion through the disaster relief bill. The Federal Emergency Management Agency (FEMA) was criticized for its slow response in both Florida and Louisiana. Even
33280-495: The country totaling about $ 250 million (1992 USD , $ 384 million 2008 USD). The severe damage primarily occurred on sparsely populated islands, and in contrast the more populated areas largely received rainfall and gusty winds. The hurricane affected about 2% of the places available for rent in the country, resulting in a drop in tourism. A total of 800 houses were destroyed, leaving 1,700 people homeless. Additionally, five schools were destroyed, and overall
33536-412: The cyclone deteriorated to tropical depression status early on August 27. Accelerating northeastward, the depression began merging with the approaching frontal system , and by midday on August 28, Andrew had lost its tropical identity while located over the southern Appalachian Mountains . The storm's remnants continued moving towards the northeast, fully merging with the remnants of Hurricane Lester and
33792-469: The deep easterlies, the depression tracked west-northwestward at 20 mph (32 km/h). Initially, moderate wind shear prevented strengthening, until a decrease in shear allowed the depression to intensify into Tropical Storm Andrew at 12:00 UTC on August 17. By the morning hours of August 18, the storm had maintained convection near its center, with spiral bands to its west, as the winds increased to 50 mph (80 km/h). Shortly thereafter,
34048-435: The development of the westerlies . Cyclone formation is usually reduced 3 days prior to the wave's crest and increased during the 3 days after. The majority of tropical cyclones each year form in one of seven tropical cyclone basins, which are monitored by a variety of meteorological services and warning centers. Ten of these warning centers worldwide are designated as either a Regional Specialized Meteorological Centre or
34304-401: The dry season the fire may be fed by organic peat and burn deeply, destroying root systems. Fires are confined by existing water and rainfall. It takes approximately 225 years for one foot (.30 m) of peat to develop, but in some locations the peat is less dense than it should be for the 5,000 years of the Everglades' existence. Scientists indicate fire as the cause; it is also cited as
34560-630: The dry season. Alligator holes are integral to the survival of aquatic invertebrates, turtles, fish, small mammals, and birds during extended drought periods. The alligators then feed upon some of the animals that come to the hole. Small islands of trees growing on land raised between 1 foot (0.30 m) and 3 feet (0.91 m) above sloughs and prairies are called tropical hardwood hammocks . They may range from one (4,000 m ) to ten acres (40,000 m ) in area, and appear in freshwater sloughs, sawgrass prairies, or pineland. Hammocks are slightly elevated on limestone plateaus risen several inches above
34816-653: The dry winter season average from 70 to 79 °F (21 to 26 °C). Frost and freeze are rare across south Florida and the Everglades; annually coastal cities like Miami and Naples report zero days with frost, although a few times each decade low temperatures may fall between 30 and 40 °F (−1 and 4 °C) across South Florida. The plant hardiness zones are 10a north with an average annual extreme minimum air temperature of 30 to 35 °F (−1 to +2 °C), and 10b south with an average annual extreme minimum air temperature of 35 to 40 °F (2 to 4 °C). Annual rainfall averages approximately 62 inches (160 cm), with
35072-405: The eastern edge of the storm. Some officials in Florida considered Andrew the worst storm in the state since the Labor Day hurricane in 1935 . But most others (particularly the media, former National Hurricane Center director Max Mayfield ) in retrospect stated that Andrew was hardly "The Big One", but still very devastating. The storm surge from Andrew was very limited in its overall coverage due
35328-486: The equator, then move poleward past the ridge axis before recurving into the main belt of the Westerlies . When the subtropical ridge position shifts due to El Niño, so will the preferred tropical cyclone tracks. Areas west of Japan and Korea tend to experience much fewer September–November tropical cyclone impacts during El Niño and neutral years. During La Niña years, the formation of tropical cyclones, along with
35584-469: The evaporation of water from the ocean surface, which ultimately condenses into clouds and rain when moist air rises and cools to saturation . This energy source differs from that of mid-latitude cyclonic storms , such as nor'easters and European windstorms , which are powered primarily by horizontal temperature contrasts . Tropical cyclones are typically between 100 and 2,000 km (62 and 1,243 mi) in diameter. The strong rotating winds of
35840-405: The eye moved onshore in Florida, the convection in the eyewall strengthened due to increased convergence, and Hurricane Hunters reported a warmer eyewall temperature than two hours prior. However, Andrew weakened as it continued further inland, and after crossing southern Florida in four hours, the storm emerged into the Gulf of Mexico with winds of 130 mph (210 km/h). In the Gulf of Mexico,
36096-418: The eye remained well-defined as the hurricane turned to the west-northwest, a change due to the weakening of the ridge to its north. Andrew steadily re-intensified over the Gulf of Mexico, reaching winds of 145 mph (233 km/h) late on August 25. As the high pressure system to its north weakened, a strong mid-latitude trough approached the area from the northwest. This caused the hurricane to decelerate to
36352-481: The eyewall of the storm, and an upper-level anticyclone helps channel this air away from the cyclone efficiently. However, some cyclones such as Hurricane Epsilon have rapidly intensified despite relatively unfavorable conditions. There are a number of ways a tropical cyclone can weaken, dissipate, or lose its tropical characteristics. These include making landfall, moving over cooler water, encountering dry air, or interacting with other weather systems; however, once
36608-519: The farthest-reaching roots, trapping sediments that help build coastlines after and between storms. All three types of trees absorb the energy of waves and storm surges . Everglades mangroves also serve as nurseries for crustaceans and fish, and rookeries for birds. The region supports Tortugas pink shrimp ( Farfantepenaeus duorarum ) and stone crab ( Menippe mercenaria ) industries; between 80 and 90 percent of commercially harvested crustacean species in Florida's salt waters are born or spend time near
36864-440: The forecast issued six hours after becoming a hurricane, the cyclone was predicted to make landfall near Jupiter, Florida , with winds of 105 mph (169 km/h) on August 25. This underestimated both the strength and the speed of the storm, which would eventually make landfall in South Florida. The hurricane accelerated westward into an area of highly favorable conditions, and began to rapidly intensify late on August 22; in
37120-410: The form of cold water from falling raindrops (this is because the atmosphere is cooler at higher altitudes). Cloud cover may also play a role in cooling the ocean, by shielding the ocean surface from direct sunlight before and slightly after the storm passage. All these effects can combine to produce a dramatic drop in sea surface temperature over a large area in just a few days. Conversely, the mixing of
37376-489: The formal request for Federal assistance that FEMA officials believed was required before they were empowered to act. President George H.W. Bush declared the region a disaster area and provided public assistance to victims in counties Broward , Collier, Dade , and Monroe . Governor Lawton Chiles considered asking the Florida Legislature to raise taxes but instead signed a bill into law on December 17 that created
37632-426: The frequency of fire help to create, maintain, or replace the ecosystems in the Everglades. Water is the dominant force in the Everglades, shaping the land, vegetation, and animal life in South Florida. Starting at the last glacial maximum , 21,000 years ago, continental ice sheets retreated and sea levels rose. This submerged portions of the Florida peninsula and caused the water table to rise. Fresh water saturated
37888-453: The frequency of very intense storms and a poleward extension of where the cyclones reach maximum intensity are among the possible consequences of human-induced climate change. Tropical cyclones use warm, moist air as their fuel. As climate change is warming ocean temperatures , there is potentially more of this fuel available. Between 1979 and 2017, there was a global increase in the proportion of tropical cyclones of Category 3 and higher on
38144-586: The frontal zone over the Mid-Atlantic , in Pennsylvania , on August 29. Post-analysis on Andrew revealed that the storm was often stronger than operationally reported between early on August 22 and early on August 26. In real time, the National Hurricane Center assessed its peak intensity as 150 mph (240 km/h), which was upgraded to 155 mph (249 km/h) in a post-storm analysis after
38400-532: The general public regarding forecasts, watches, and warnings. Since the systems can last a week or longer, and more than one can be occurring in the same basin at the same time, the names are thought to reduce the confusion about what storm is being described. Names are assigned in order from predetermined lists with one, three, or ten-minute sustained wind speeds of more than 65 km/h (40 mph) depending on which basin it originates. Standards vary from basin to basin. Some tropical depressions are named in
38656-426: The growth of sawgrass, whereas a shorter hydroperiod of six months or less promotes beds of periphyton , a growth of algae and other microscopic organisms. There are only two types of soil in the Everglades, peat and marl . Where there are longer hydroperiods, peat builds up over hundreds or thousands of years due to many generations of decaying plant matter. Where periphyton grows, the soil develops into marl, which
38912-447: The hammocks very difficult for people to penetrate, though small mammals, reptiles and amphibians find these islands an ideal habitat. Water in sloughs flows around the islands, creating moats . Although some ecosystems are maintained and promoted by fire, hammocks may take decades or centuries to recover. The moats around the hammocks protect the trees. The trees are limited in height by weather factors such as frost, lightning, and wind;
39168-575: The history of Florida, mostly along Interstate 95 . United States Coast Guard vessels on or near the Florida coastline were either secured onshore or sent to ride out the storm at sea. Government offices and public and private schools were closed from Monroe County northward to St. Lucie County . Many colleges and universities in southeast Florida also closed. Major airports such as the Fort Lauderdale–Hollywood , Key West , Miami , and Palm Beach international airports closed. Shortly after
39424-732: The homes destroyed or severely damaged throughout Dade County, 36,000 had been restored by July 1994. Over 930,000 policyholders in South Florida lost coverage after 11 insurance companies went bankrupt, resulting in over 600,000 insurance claims. The Florida Legislature created new entities like the Joint Underwriting Association, Florida Windstorm Underwriting Association, and Florida Hurricane Catastrophe Fund to restore insurance capacity. Stricter building codes were established in Florida after Hurricane Andrew. A survey by Timothy P. Marshall and Richard Herzog of
39680-538: The houses in the village were destroyed, and the rest of the buildings sustained minor to major damage. On nearby Current Island, the hurricane destroyed 24 of the 30 houses in the village. The island's only road was heavily damaged, with parts still flooded more than a week after the storm. The hurricane was estimated to have spawned several tornadoes in Eleuthera district, based on a subsequent analysis of damage to buildings and shrubbery; tornadoes were also reported in
39936-464: The hurricane alerts." The same report cited the public "[exhibiting] a degree of complacency, particularly in New Providence and The Current, Eleuthera." Ultimately, the advance warning of the hurricane contributed to the low death toll from the storm. The hurricane struck four days after Hubert Ingraham became Bahamian Prime Minister, the first new Prime Minister in 25 years. There was initially
40192-780: The hurricane produced storm tides of at least 8 ft (2.4 m) above normal, causing flooding along the coast from Vermilion Bay to Lake Borgne . Offshore, a group of six fishermen from Alabama drowned. Heavy rains accompanied the storm's passage through the state, peaking at 11.02 in (280 mm) in Robert . River flooding was also reported, with the Tangipahoa River in Robert cresting at 3.8 ft (1.2 m) above flood stage. Before making landfall, Andrew spawned an F3 tornado in LaPlace , which killed two people and injured 32. The tornado
40448-415: The hurricane stripped many homes of all but their concrete foundations and caused catastrophic damage. In total, Andrew destroyed more than 63,500 houses, damaged more than 124,000 others, caused $ 27.3 billion in damage (equivalent to $ 61 billion in 2024), and left 65 people dead. Andrew began as a tropical depression over the eastern Atlantic Ocean on August 16. After spending
40704-465: The hurricane. With 23,000 houses damaged, 985 others destroyed, and 1,951 mobile homes demolished, property losses in Louisiana exceeded $ 1.5 billion. The hurricane caused the deaths of 17 people in the state, 6 of whom drowned offshore. Andrew spawned at least 28 tornadoes along the Gulf Coast, especially in Alabama , Georgia , and Mississippi . In total, Andrew left 65 dead and caused $ 27.3 billion in damage. Andrew
40960-451: The intensity from leveling off before an eye emerges in infrared imagery. The SATCON weights estimates from various satellite-based systems and microwave sounders , accounting for the strengths and flaws in each individual estimate, to produce a consensus estimate of a tropical cyclone's intensity which can be more reliable than the Dvorak technique at times. Multiple intensity metrics are used, including accumulated cyclone energy (ACE),
41216-522: The intensity of a tropical cyclone. Reconnaissance aircraft fly around and through tropical cyclones, outfitted with specialized instruments, to collect information that can be used to ascertain the winds and pressure of a system. Tropical cyclones possess winds of different speeds at different heights. Winds recorded at flight level can be converted to find the wind speeds at the surface. Surface observations, such as ship reports, land stations, mesonets , coastal stations, and buoys, can provide information on
41472-456: The island of Eleuthera , which has a population of around 8,000, and is generally about 1.6 km (0.99 mi) in width. Prior to its arrival, the hurricane caused the coastline to recede about 3 mi (4.8 km), which was followed by what was described as a "mighty wall of water", or a storm surge . The Current, a small village in the northwestern portion of the island, recorded a surge of 7.2 m (24 ft). There, more than half of
41728-415: The island's marina received heavy damage, with hundreds of trees downed by the strong winds. Later, Hurricane Andrew made its second landfall in the Berry Islands early on August 24 as a Category 4 hurricane on the Saffir-Simpson scale. Damage was heavy and estimated "in the millions of dollars". Overall, Andrew caused about $ 25.3 billion in damage in Florida, making it the costliest hurricane to hit
41984-416: The islands with storm surge , hurricane-force winds , and tornadoes . About 800 houses were destroyed in the archipelago, and there was substantial damage to the transport, water, sanitation, agriculture, and fishing sectors. Andrew left four dead and $ 250 million in damage throughout The Bahamas. In parts of southern Florida, Andrew produced severe winds; a wind gust of 177 mph (285 km/h)
42240-446: The key mechanism by which water leaves the region. During a year unaffected by drought, the rate may reach 40 inches (100 cm) a year. When droughts take place, the rate may peak at over 50 inches (130 cm), and exceed the amount of rainfall. As water leaves an area through evaporation from groundwater or from plant matter, activated primarily by solar energy, it is then moved by wind patterns to other areas that border or flow into
42496-449: The landfall winds were decreased from 120 to 115 mph (193 to 185 km/h). At 1500 UTC on August 22, about 30 hours prior to landfall, the government of the Bahamas issued a hurricane watch for the northwest Bahamas , including Andros and Eleuthera islands, northward through Grand Bahama and Great Abaco . Six hours later, the watch was upgraded to a hurricane warning , and about 15 hours before landfall
42752-446: The largest body of water in the park boundaries. There are approximately 100 keys in Florida Bay, many of which are mangrove forests. The fresh water coming into Florida Bay from the Everglades creates perfect conditions for vast beds of turtle grass and algae formations that are the foundation for animal life in the bay. Sea turtles and manatees eat the grass, while invertebrate animals, such as worms, clams and other mollusks eat
43008-582: The late 1800s and early 1900s and gradually superseded the existing system—simply naming cyclones based on what they hit. The system currently used provides positive identification of severe weather systems in a brief form, that is readily understood and recognized by the public. The credit for the first usage of personal names for weather systems is generally given to the Queensland Government Meteorologist Clement Wragge who named systems between 1887 and 1907. This system of naming weather systems fell into disuse for several years after Wragge retired, until it
43264-425: The limestone that underlies the Everglades, eroding some of it away, and created springs and sinkholes . The abundance of fresh water allowed new vegetation to take root, and formed convective thunderstorms over the land through evaporation. As rain continued to fall, the slightly acidic rainwater dissolved the limestone. As limestone wore away, the groundwater came into contact with the land surface and created
43520-404: The main belt of the Westerlies , by means of merging with a nearby frontal zone, can cause tropical cyclones to evolve into extratropical cyclones . This transition can take 1–3 days. Should a tropical cyclone make landfall or pass over an island, its circulation could start to break down, especially if it encounters mountainous terrain. When a system makes landfall on a large landmass, it
43776-513: The majority of trees in hammocks grow no higher than 55 feet (17 m). Some of the driest land in the Everglades is pineland (also called pine rockland) ecosystem, located in the highest part of the Everglades with little to no hydroperiod. Some floors, however, may have flooded solution holes or puddles for a few months at a time. The most significant feature of the pineland is the single species of South Florida slash pine ( Pinus elliottii ). Pineland communities require fire to maintain them, and
44032-526: The marl can support a variety of water plants. Solution holes , or deep pits where the limestone has worn away, may remain flooded even when the prairies are dry, and they support aquatic invertebrates such as crayfish and snails, and larval amphibians which feed young wading birds. These regions tend to border between sloughs and sawgrass marshes. Alligators have created a niche in wet prairies. With their claws and snouts they dig at low spots and create ponds free of vegetation that remain submerged throughout
44288-420: The mouths of rivers or on key islands. The Calusa were hunter-gatherers who lived on small game, fish, turtles, alligators, shellfish, and various plants. Most of their tools were made of bone or teeth, although sharpened reeds were also effective for hunting or war. Calusa weapons consisted of bows and arrows, atlatls , and spears. Canoes were used for transportation, and South Florida tribes often canoed through
44544-558: The natural water system in the Everglades. The Everglades are a complex system of interdependent ecosystems. Marjory Stoneman Douglas described the area as a "River of Grass" in 1947, though that metaphor represents only a portion of the system. The area recognized as the Everglades, prior to drainage, was a web of marshes and prairies 4,000 square miles (10,000 km ) in size. Borders between ecosystems are subtle or imperceptible. These systems shift, grow and shrink, die, or reappear within years or decades. Geologic factors, climate, and
44800-407: The nearby districts of Harbour Island and Spanish Wells . Towns south of where Andrew moved ashore received fairly minor damage, although the control tower at Governor's Harbour Airport was destroyed. High surf caused damage to roads and docks along the coast. In Spanish Wells, located near the north coast of Eleuthera, three buildings were destroyed, and a bridge connecting to a neighboring island
45056-469: The north of the storm's path, sustained winds up to 98 mph (158 km/h) were observed in Chokoloskee . Storm surge flooded low-lying areas, particularly in Goodland, Everglades City, and Marco Island. Many boats were damaged or destroyed by the rough seas and strong winds. The storm destroyed 80 mobile homes and severely damaged 400 others. Property damage in the county reached about $ 30 million. After hitting Florida, Andrew moved across
45312-472: The northern island chain in Exuma , and the three districts on Grand Bahama . At the capital city of Nassau , sustained winds reached 92 mph (148 km/h), while gusts up to 115 mph (185 km/h) were reported. Harbour Island , near Eleuthera, reported wind gusts of 138 mph (222 km/h) – the strongest gust speed observed in the Bahamas during Andrew's passage. Much of the northwestern Bahamas received damage, with monetary damage throughout
45568-411: The northwest, and winds decreased as Andrew approached the Gulf Coast of the United States . At 08:30 UTC on August 26, the cyclone made landfall about 20 mi (32 km) west-southwest of Morgan City, Louisiana, with winds of 115 mph (185 km/h). Andrew weakened rapidly as it turned to the north and northeast, falling to tropical storm intensity within 10 hours. After entering Mississippi,
45824-462: The observed trend of rapid intensification of tropical cyclones in the Atlantic basin. Rapidly intensifying cyclones are hard to forecast and therefore pose additional risk to coastal communities. Warmer air can hold more water vapor: the theoretical maximum water vapor content is given by the Clausius–Clapeyron relation , which yields ≈7% increase in water vapor in the atmosphere per 1 °C (1.8 °F) warming. All models that were assessed in
46080-459: The ocean. Mangrove trees are well adapted to the transitional zone of brackish water where fresh and salt water meet. The estuarine ecosystem of the Ten Thousand Islands , which is comprised almost completely of mangrove forests, covers almost 200,000 acres (810 km ). In the wet season fresh water pours out into Florida Bay, and sawgrass begins to grow closer to the coastline. In the dry season, and particularly in extended periods of drought,
46336-466: The overall frequency of tropical cyclones worldwide, with increased frequency in the North Atlantic and central Pacific, and significant decreases in the southern Indian Ocean and western North Pacific. There has been a poleward expansion of the latitude at which the maximum intensity of tropical cyclones occurs, which may be associated with climate change. In the North Pacific, there may also have been an eastward expansion. Between 1949 and 2016, there
46592-498: The parish suffered $ 125 million in property damage, while an additional $ 200 million in damage was inflicted on sugar crops. Across the state, the hurricane damaged 23,000 homes and destroyed 985 homes and 1,951 mobile homes; private property damage was estimated at $ 1 billion. The high winds destroyed large areas of sugar and soybean crops, estimated at $ 289 million in damage. Strong winds also left at least 230,000 people without electricity. During
46848-461: The passage of Andrew. Further west, damage on Andros Island was fairly minor and limited to the northernmost portion of the island. One dock was destroyed, and two parks were severely damaged. On South Bimini , the storm caused light damage, including to two hotels on the island. The private island of Cat Cay in the Bimini Islands was severely impacted by the hurricane, with damage estimated at $ 100 million (1992 USD). Many wealthy homes and
47104-452: The path of the storm, along with 26 tornadoes. Structural damage was generally minimal, occurring from the tornadoes and severe thunderstorms. One tornado in Kemper County destroyed a mobile home, while another twister in Lauderdale County demolished a mobile home, damaged five other dwellings, and injured four people. Additionally, a possible tornado damaged a home and two trailers in Lawrence County . Strong winds knocked down trees in
47360-410: The path of the storm. In addition, the National Hurricane Center noted the likelihood of isolated tornadoes in Central and South Florida during the passage of Andrew on August 23 and 24. Several tropical storm and hurricane warnings were issued for much of Central and South Florida, from Titusville on the east coast to Venice on the west coast. Included in the warnings were Lake Okeechobee and all of
47616-443: The peat into carbon dioxide and water. Some of the peat was burned by settlers to clear the land. Some homes built in the areas of early farms had to have their foundations moved to stilts as the peat deteriorated; other areas lost approximately 8 feet (2.4 m) of soil depth. Fire is an important element in the natural maintenance of the Everglades. The majority of fires are caused by lightning strikes from thunderstorms during
47872-480: The people lived in relative isolation from the majority culture. The construction of the Tamiami Trail , beginning in 1928 and spanning the region from Tampa to Miami, altered their ways of life. Some began to work in local farms, ranches, and souvenir stands. Some of the people who interacted more with European Americans began to move to reservations in the 1940s. These were their bases for reorganizing their government and they became federally recognized in 1957 as
48128-440: The potential of spawning tornadoes . Climate change affects tropical cyclones in several ways. Scientists found that climate change can exacerbate the impact of tropical cyclones by increasing their duration, occurrence, and intensity due to the warming of ocean waters and intensification of the water cycle . Tropical cyclones draw in air from a large area and concentrate the water content of that air into precipitation over
48384-413: The presence of moderate or strong wind shear depending on the evolution and structure of the storm's convection. The size of tropical cyclones plays a role in how quickly they intensify. Smaller tropical cyclones are more prone to rapid intensification than larger ones. The Fujiwhara effect , which involves interaction between two tropical cyclones, can weaken and ultimately result in the dissipation of
48640-410: The reason for the black color of Everglades muck. Layers of charcoal have been detected in the peat in portions of the Everglades that indicate the region endured severe fires for years at a time, although this trend seems to have abated since the last occurrence in 940 BC . Several ecosystems are present in the Everglades, and boundaries between them are subtle or absent. The primary feature of
48896-403: The region where the Tequesta lived. Common descriptions of Native Americans in Florida by 1820 used only the term "Seminoles". Following the demise of the Calusa and Tequesta, Native Americans in southern Florida were referred to as "Spanish Indians" in the 1740s, probably due to their friendlier relations with Spain. The Creek invaded the Florida peninsula; they conquered and assimilated what
49152-486: The region. The deterioration of the Everglades, including poor water quality in Lake Okeechobee , was linked to the diminishing quality of life in South Florida's urban areas. In 2000 the Comprehensive Everglades Restoration Plan was approved by Congress to combat these problems, which at that time was considered the most expensive and comprehensive environmental restoration attempt in history; however, implementation faced political complications. The first written record of
49408-444: The release of latent heat from the saturated soil. Orographic lift can cause a significant increase in the intensity of the convection of a tropical cyclone when its eye moves over a mountain, breaking the capped boundary layer that had been restraining it. Jet streams can both enhance and inhibit tropical cyclone intensity by influencing the storm's outflow as well as vertical wind shear. On occasion, tropical cyclones may undergo
49664-434: The river over it. Much less permeable, this formation is highly calcitic and is composed of sandy shell marl, clay, and sand. Water underneath the Caloosahatchee Formation is typically very mineralized. Both the Tamiami and Caloosahatchee Formations developed during the Pliocene Epoch . Surrounding the southern part of Lake Okeechobee is the Fort Thompson Formation, made of dense, hard limestone, shells, and sand. Rain water
49920-410: The rock is especially porous and stores water during the dry season in the Everglades, and its chemical composition determines the vegetation prevalent in the region. The Miami Oolite facies also acts to impede flow of water from the Everglades to the ocean between Fort Lauderdale and Coot Bay (near Cape Sable ). The metropolitan areas of Miami , Fort Lauderdale, and West Palm Beach are located on
50176-539: The rock underneath the Everglades can be explained by the geologic history of the state. The crust underneath Florida was at one point part of the African region of the supercontinent Gondwana . About 300 million years ago, North America merged with Africa, connecting Florida with North America. Volcanic activity centered on the eastern side of Florida covered the prevalent sedimentary rock with igneous rock . Continental rifting began to separate North America from Gondwana about 180 million years ago. When Florida
50432-667: The salt water creeps inland into the coastal prairie, an ecosystem that buffers the freshwater marshes by absorbing sea water. Mangrove trees begin to grow in fresh water ecosystems when the salt water goes far enough inland. There are three species of trees that are considered mangroves: red ( Rhizophora mangle ), black ( Avicennia germinans ), and white ( Laguncularia racemosa ), although all are from different families. All grow in oxygen-poor soil, can survive drastic water level changes, and are tolerant of salt, brackish, and fresh water. All three mangrove species are integral to coastline protection during severe storms. Red mangroves have
50688-492: The same intensity. The passage of a tropical cyclone over the ocean causes the upper layers of the ocean to cool substantially, a process known as upwelling , which can negatively influence subsequent cyclone development. This cooling is primarily caused by wind-driven mixing of cold water from deeper in the ocean with the warm surface waters. This effect results in a negative feedback process that can inhibit further development or lead to weakening. Additional cooling may come in
50944-441: The same system. The ASCAT is a scatterometer used by the MetOp satellites to map the wind field vectors of tropical cyclones. The SMAP uses an L-band radiometer channel to determine the wind speeds of tropical cyclones at the ocean surface, and has been shown to be reliable at higher intensities and under heavy rainfall conditions, unlike scatterometer-based and other radiometer-based instruments. The Dvorak technique plays
51200-513: The sea can result in heat being inserted in deeper waters, with potential effects on global climate . Vertical wind shear decreases tropical cyclone predicability, with storms exhibiting wide range of responses in the presence of shear. Wind shear often negatively affects tropical cyclone intensification by displacing moisture and heat from a system's center. Low levels of vertical wind shear are most optimal for strengthening, while stronger wind shear induces weakening. Dry air entraining into
51456-488: The season ended. However, a 2004 paper by Christopher Landsea and others concluded that Andrew became a Category 5 hurricane near the Bahamas on August 23 and reached maximum sustained winds of 175 mph (282 km/h). The paper also indicated that Andrew briefly re-intensified into a Category 5 hurricane around the time of landfall in South Florida early on August 24. The storm was found to have been slightly stronger than originally assessed while approaching Louisiana, but
51712-572: The slowly moving water, but may die in unusually deep floods if oxygen is unable to reach its roots. It is particularly vulnerable immediately after a fire. The hydroperiod for the marsh is at least nine months, and can last longer. Where sawgrass grows densely, few animals or other plants live, although alligators choose these locations for nesting. Where there is more room, periphyton grows. Periphyton supports larval insects and amphibians, which in turn are consumed as food by birds, fish, and reptiles. It also absorbs calcium from water, which adds to
51968-459: The small forest the appearance of a dome from the outside. They also grow in strands, slightly elevated on a ridge of limestone bordered on either side by sloughs. Other hardwood trees can be found in cypress domes, such as red maple , swamp bay , and pop ash . If cypresses are removed, the hardwoods take over, and the ecosystem is recategorized as a mixed swamp forest. Eventually the water from Lake Okeechobee and The Big Cypress makes its way to
52224-452: The small number of resort lodgings affected (around 2%), officials expected a 10–20% decline in tourism. The Government of the Bahamas , observing that their response mechanisms were not sufficient, reformed the National Emergency and Management Agency. The passage of the hurricane disrupted several breeding colonies of the white-crowned pigeon throughout the country. Though the hurricane did not affect many tourist areas, officials predicted
52480-573: The southeastern United States along the Appalachian Mountains corridor; totals of over 5 in (130 mm) were reported where Georgia and South Carolina meet North Carolina. In West Virginia , the remnants of Andrew combined with a cold front to produce 1.5 to 2.5 in (38 to 64 mm) of rain over portions of the state, causing flooding in areas of Morgantown with poor drainage. The remnants of Andrew also spawned several tornadoes in Maryland . A tornado in Howard County damaged several homes, some extensively. The twister also tossed and wrecked
52736-455: The southern portion of the Florida peninsula dates to 15,000 years ago. Before European colonization, the region was dominated by the native Calusa and Tequesta tribes. With Spanish colonization, both tribes declined gradually during the following two centuries. The Seminole , formed from mostly Creek people who had been warring to the North, assimilated other peoples and created a new culture after being forced from northern Florida into
52992-415: The southwestern portion of the state. Much of Mississippi received 3 to 5 in (76 to 127 mm) of rain, while areas near the southwest corner of the state observed over 7 in (180 mm) of precipitation, with a peak of 9.30 in (236 mm) at Sumrall . Flooding was mostly limited to the inundation of minor roads and low-lying areas in several counties. In Alabama, precipitation amounts in
53248-411: The state at the time. Some estimates in Florida put the damage as high as $ 34 billion (1992 USD , $ 73.8 billion 2024 USD). Almost all of the damage in Florida was caused by strong winds, rather than storm surge or flooding that is usually associated with a major hurricane. Of the 44 deaths attributed to the storm, 15 were direct fatalities, while 29 were indirectly caused by
53504-431: The state peaked at 4.71 in (120 mm) in Aliceville . The rainfall caused flooding in low-lying areas and creeks, covering a few county roads but not entering many houses or businesses. Along the coast, the storm produced flooding and high tides. Along Dauphin Island , high tides left severe beach erosion , with portions of the island losing up to 30 ft (9.1 m) of sand. Three damaging tornadoes occurred in
53760-402: The state reached about $ 100,000. In Tennessee , thunderstorm winds and tornadoes associated with Andrew downed trees and power lines, but caused little overall impact to homes and buildings. Similarly, in North Carolina , thunderstorm winds toppled trees and power lines at a number of locations in the mountainous areas of the state, especially in Avery County . Rainfall from Andrew spread across
54016-431: The state. The most damaging tornado was spawned in Elmore County and moved from an area northeast of Montgomery to the south of Wetumpka and briefly lifted during its 0.5 mi (0.80 km) track. The tornado destroyed 2 homes and damaged 18 homes, 1 mobile home, 2 barns, and 1 vehicle. One person was injured by the twister. Sustained winds in the state were below tropical storm force, though
54272-428: The storm also caused major damage in The Bahamas and Louisiana , the greatest impact was felt in South Florida , where the storm made landfall as a Category 5 hurricane, with 1-minute sustained wind speeds as high as 165 mph (266 km/h) and a gust as high as 174 mph (280 km/h). Passing directly through the cities of Cutler Bay and Homestead in Dade County (now known as Miami-Dade County),
54528-497: The storm began to lose velocity due to increased southwesterly wind shear from an upper-level low. On August 19, a Hurricane Hunters flight into the storm failed to locate a well-defined center and on the following day, a flight found that the cyclone had degenerated to the extent that only a diffuse low-level circulation center remained; observations indicated the barometric pressure rose to an unusually high 1,015 mbar (29.97 inHg). The flight indicated that Andrew maintained
54784-431: The storm emerged into the Gulf of Mexico from southern Florida, the National Hurricane Center issued hurricane watches and warnings for the Gulf Coast of the United States beginning at 13:00 UTC on August 24. After the initial hurricane watch from Mobile, Alabama , to Sabine Pass, Texas , the watches and warnings were expanded to eventually include areas from Mobile, Alabama, to Freeport, Texas . All watches and warnings on
55040-455: The storm left severe damage to the sectors of transport, communications, water, sanitation, agriculture, and fishing. The hurricane caused four deaths in the country, of which three directly; the indirect fatality was due to a heart failure during the passage of the storm. Hurricane Andrew first made landfall on August 23 as a Category 5 hurricane on the Saffir-Simpson scale , with winds of 260 km/h (160 mph). The hurricane struck
55296-455: The storm was active, urged residents to "take this hurricane seriously". Before the hurricane passed through the Bahamas, forecasters predicted a storm surge of up to 18 ft (5.5 m), as well as up to 8 in (200 mm) of rain. In a subsequent analysis by Arthur Rolle, the Bahamas Chief Meteorological Officer, national emergency agencies including the Red Cross and the Royal Bahamas Defence Force "responded exceptionally well to
55552-433: The storm were confined to a relatively small area, stretching from Key Largo to the Miami Beach area. A house near Perrine initially reported a wind gust of 212 mph (341 km/h) before the structure and instrument were destroyed; this measurement was reduced to 177 mph (285 km/h), after wind-tunnel testing at the Virginia Polytechnic Institute and State University of the same type of anemometer revealed
55808-423: The storm were disposed of. Tides were generally between 4 and 6 ft (1.2 and 1.8 m) above normal in the Biscayne Bay area, though near the Burger King International Headquarters , tides reached as high as 16.9 ft (5.2 m) above normal. Storm surge on the west coast was widespread but generally light, with a peak height of 6 ft (1.8 m) in Everglades City and Goodland . Strong winds from
56064-436: The storm's passage, upwelling occurred in the Atchafalaya Basin and Bayou Lafourche , killing 187 million freshwater fish. Damage to the fishing industry was estimated at $ 266 million. Overall, losses in the state of Louisiana reached approximately $ 1.56 billion. A total of 17 deaths occurred in Louisiana, 8 directly and 9 from indirect causes. At least 75 injuries were reported. While Andrew
56320-431: The storm. It was later noted that if Andrew had been slightly larger or made landfall a few miles further north, it would have significantly affected Miami and Fort Lauderdale , which would have resulted in an even higher damage and death toll. An analysis by the American Meteorological Society indicated that unlike most hurricanes, wind damage from Andrew was mostly north of the geometric center and occurred primarily on
56576-433: The storm. To provide temporary housing for the homeless, military personnel initially set up a total of five tent cities in Florida City and Homestead, while a sixth tent city was opened at the Miccosukee Indian Reservation shortly after Labor Day weekend. The Government of Canada dispatched a team of 90 military engineers to repair community centers, hospitals, and schools, and a crew of 300 military personnel
56832-419: The subtropical ridge position, shifts westward across the western Pacific Ocean, which increases the landfall threat to China and much greater intensity in the Philippines . The Atlantic Ocean experiences depressed activity due to increased vertical wind shear across the region during El Niño years. Tropical cyclones are further influenced by the Atlantic Meridional Mode , the Quasi-biennial oscillation and
57088-419: The surface pressure decreases by 2.5 hPa (0.074 inHg) per hour for at least 12 hours or 5 hPa (0.15 inHg) per hour for at least 6 hours. For rapid intensification to occur, several conditions must be in place. Water temperatures must be extremely high, near or above 30 °C (86 °F), and water of this temperature must be sufficiently deep such that waves do not upwell cooler waters to
57344-483: The surface. On the other hand, Tropical Cyclone Heat Potential is one of such non-conventional subsurface oceanographic parameters influencing the cyclone intensity. Wind shear must be low. When wind shear is high, the convection and circulation in the cyclone will be disrupted. Usually, an anticyclone in the upper layers of the troposphere above the storm must be present as well—for extremely low surface pressures to develop, air must be rising very rapidly in
57600-420: The surrounding peat, or they may grow on land that has been unharmed by deep peat fires. Hardwood hammocks exhibit a mixture of subtropical and hardwood trees, such as Southern live oak ( Quercus virginiana ), gumbo limbo ( Bursera simaruba ), royal palm ( Roystonea ), and bustic ( Dipholis salicifolia ) that grow in very dense clumps. Near the base, sharp saw palmettos ( Serenoa repens ) flourish, making
57856-435: The system and its intensity. For example, within the Northern Atlantic and Eastern Pacific basins, a tropical cyclone with wind speeds of over 65 kn (120 km/h; 75 mph) is called a hurricane , while it is called a typhoon or a severe cyclonic storm within the Western Pacific or North Indian oceans. When a hurricane passes west across the International Dateline in the Northern Hemisphere, it becomes known as
58112-415: The trees have several adaptations that simultaneously promote and resist fire. The sandy floor of the pine forest is covered with dry pine needles that are highly flammable. South Florida slash pines are insulated by their bark to protect them from heat. Fire eliminates competing vegetation on the forest floor , and opens pine cones to germinate seeds. A period without significant fire can turn pineland into
58368-423: The tropical cyclone year begins on July 1 and runs all year-round encompassing the tropical cyclone seasons, which run from November 1 until the end of April, with peaks in mid-February to early March. Of various modes of variability in the climate system, El Niño–Southern Oscillation has the largest effect on tropical cyclone activity. Most tropical cyclones form on the side of the subtropical ridge closer to
58624-643: The vast majority in Dade County – with about 175,000 people rendered homeless. Smaller tropical cyclones like Andrew or Charley tend to produce less overall coverages and damage from the storm surge, in contrast to hurricanes such as Hugo , Ike , Ivan , and Katrina . In addition to homes, the storm damaged or destroyed 82,000 businesses, 32,900 acres (13,300 ha) of farmland, 31 public schools, 59 health facilities/hospitals, 9,500 traffic signals, 3,300 mi (5,300 km) of power lines, and 3,000 watermains. Approximately 20 million cubic yards (15 million m ) of debris left by
58880-482: The vast majority of the damage from the hurricane, totaling approximately $ 25 billion. Andrew left at least 40 deaths in the county, 15 direct and 25 indirect. Elsewhere, effects were relatively minimal, except in Broward, Monroe, and Collier counties. In Broward County, on the north side of the storm's path, damage in several municipalities was primarily limited to downed trees, several of which fell onto roads and power lines. In Pembroke Park , one of
59136-435: The warm waters of the Gulf Stream , the hurricane rapidly re-intensified as the eye decreased in size and its eyewall convection deepened. At 08:40 UTC on August 24, Andrew struck Elliott Key as a Category 5 hurricane, with winds of 165 mph (266 km/h) and a pressure of 926 mbar (27.34 inHg). About 25 minutes after its first Florida landfall, Andrew made another landfall just northeast of Homestead, with
59392-439: The wave axis to the south of the Cape Verde islands, and on August 15, meteorologists began classifying the system with the Dvorak technique . The thunderstorm activity became more concentrated, and narrow spiral rainbands began to develop around a center of circulation . It is estimated that Tropical Depression Three developed late on August 16, about 1,630 mi (2,620 km) east-southeast of Barbados . Embedded within
59648-451: The weaker of two tropical cyclones by reducing the organization of the system's convection and imparting horizontal wind shear. Tropical cyclones typically weaken while situated over a landmass because conditions are often unfavorable as a result of the lack of oceanic forcing. The Brown ocean effect can allow a tropical cyclone to maintain or increase its intensity following landfall , in cases where there has been copious rainfall, through
59904-429: The wet season. Their effects are largely superficial, and serve to foster specific plant growth: sawgrass will burn above water, but the roots are preserved underneath. Fire in the sawgrass marshes serves to keep out larger bushes and trees, and releases nutrients from decaying plant matter more efficiently than decomposition . Whereas in the wet season, dead plant matter and the tips of grasses and trees are burned, in
60160-462: The whole show". Some FEMA officials responded that it was impossible to respond as they had been requested while also continuing to provide aid for the Los Angeles riots . FEMA spokesman Grant Peterson stated, "24 hours is not reasonable to expect to have all the resources of the federal government landing in the middle of a disaster." Some responsibility for the slow response must rest with Florida Governor Lawton Chiles , who waited five days to submit
60416-402: The wind speed of Hurricane Helene by 11%, it increased the destruction from it by more than twice. According to World Weather Attribution the influence of climate change on the rainfall of some latest hurricanes can be described as follows: Tropical cyclone intensity is based on wind speeds and pressure. Relationships between winds and pressure are often used in determining the intensity of
60672-423: The worst affected cities in the county, approximately 260 mobile homes were damaged. Storm surge left coastal flooding in some areas, especially along state roads A1A and 858 . Property damage reached about $ 100 million and three fatalities were reported in Broward County. In Everglades National Park and Biscayne National Park , more than 25% of trees were damaged or destroyed, including one-fourth of
60928-426: Was sugarcane . Approximately 50 percent of the original Everglades has been developed as agricultural or urban areas. Following this period of rapid development and environmental degradation, the ecosystem began to receive notable attention from conservation groups in the 1970s. Internationally, UNESCO and the Ramsar Convention designated the Everglades a Wetland Area of Global Importance. The construction of
61184-659: Was 185 kn (95 m/s; 345 km/h; 215 mph) in Hurricane Patricia in 2015—the most intense cyclone ever recorded in the Western Hemisphere . Warm sea surface temperatures are required for tropical cyclones to form and strengthen. The commonly-accepted minimum temperature range for this to occur is 26–27 °C (79–81 °F), however, multiple studies have proposed a lower minimum of 25.5 °C (77.9 °F). Higher sea surface temperatures result in faster intensification rates and sometimes even rapid intensification . High ocean heat content , also known as Tropical Cyclone Heat Potential , allows storms to achieve
61440-475: Was a slowdown in tropical cyclone translation speeds. It is unclear still to what extent this can be attributed to climate change: climate models do not all show this feature. A 2021 study review article concluded that the geographic range of tropical cyclones will probably expand poleward in response to climate warming of the Hadley circulation . When hurricane winds speed rise by 5%, its destructive power rise by about 50%. Therfore, as climate change increased
61696-399: Was also the strongest landfalling hurricane in the United States in decades and the costliest hurricane to strike anywhere in the country, until it was surpassed by Katrina in 2005 . Andrew is one of only four tropical cyclones to make landfall in the continental United States as a Category 5, alongside the 1935 Labor Day hurricane , 1969's Camille , and 2018's Michael . While
61952-413: Was approaching, an estimated 20,000–30,000 tourists were in the Florida Keys (Monroe County). Overall, almost 1.2 million people evacuated, which contributed to the low number of fatalities, despite the intensity of the storm. Many evacuees also checked into hotels, with rooms completely booked as far north as Ocala . Ultimately, the sheer number of evacuees led to likely the largest traffic jam in
62208-456: Was deroofed during the storm. Generally, single-family homes fared well, with most losing only roofing shingles, though others suffered severe damage after large trees fell on them. In Cypremort Point State Park , several mobile homes were destroyed. Houses in Berwick, Morgan City, and Patterson suffered major damage. Throughout the parish, 1,367 dwellings were destroyed, 2,028 were severely damaged, and 4,770 others were impacted to
62464-447: Was destroyed. Though Andrew was moving fast, rainfall in Florida was substantial in a few areas (less in others); the rainfall peaked at 13.98 inches (355 mm) in western Dade County. Andrew was considered a "dry hurricane" by multiple media networks. In Florida, Andrew killed 44 and left a then-record $ 25 billion in damage. Prior to making landfall in Louisiana on August 26, Andrew caused extensive damage to oil platforms in
62720-480: Was entering the Gulf of Mexico, oil companies evacuated hundreds of employees from offshore drilling platforms. The storm damaged 241 oil and gas facilities and toppled 33 platforms off the coast of Louisiana, causing significant disruptions in production. Additionally, 83 pipeline segments suffered damage to some degree. The oil industry lost about $ 12 million per day in the days following Andrew and $ 4 million daily by three weeks later. Initially,
62976-405: Was generally minor. In Carroll County , several dwellings and barns were damaged, with one mobile home destroyed. At the Columbus Metropolitan Airport , buildings, billboards, and signs were damaged. Additionally, a tornado in Floyd County near Rome snapped and uprooted several trees, damaged several fences and homes, and flipped over a trailer, tossing it on top of four cars. Monetary losses in
63232-409: Was labeled " Pa-hai-okee " on a U.S. military map from 1839, although it had earlier been called "Ever Glades" throughout the Second Seminole War . A 2007 survey by geographers Ary J. Lamme and Raymond K. Oldakowski found that the "Glades" has emerged as a distinct vernacular region of Florida. It comprises the interior areas and southernmost Gulf Coast of South Florida , largely corresponding to
63488-492: Was left of pre-Columbian societies into the Creek Confederacy. They were joined by remnant Indian groups and formed the Seminole, a new tribe, by ethnogenesis . The Seminole originally settled in the northern portion of the territory. In addition, free blacks and fugitive slaves made their way to Florida, where Spain had promised slaves freedom and arms if they converted to Catholicism and pledged loyalty to Spain. These African Americans gradually created communities near those of
63744-421: Was observed at a house in Perrine . The cities of Florida City , Homestead, Cutler Ridge , and parts of Kendall received the brunt of Andrew. As many as 1.4 million people lost power at the height of the storm, some for more than one month. In the Everglades , 70,000 acres (280 km) of trees were downed, while invasive Burmese pythons began inhabiting the region after a nearby facility housing them
64000-622: Was on the ground for about 10 minutes, during which it damaged or destroyed 163 structures, leaving 60 families homeless. Collectively, 14 tornadoes were reported in the parishes of Ascension , Iberville , Pointe Coupee , and Avoyelles , as well as in Baton Rouge . Along the Louisiana coastline, damage largely resembled that of a Category 2 hurricane. Damage was heaviest in St. Mary Parish , about 32 mi (51 km) east of where Andrew made landfall. Twenty-six schools were affected, with damage totaling $ 2.6 million. Berwick High School , sheltering about 2,000 people,
64256-573: Was ordered by Mayor Andy Valence and the city council. In New Orleans , Mayor Sidney Barthelemy ordered the evacuation of about 200,000 residents in the low-lying areas of the city. Nine shelters were opened in the city, which were occupied by thousands of people. In response to computer simulations showing that storm surge from a tropical cyclone like Hurricane Andrew could over-top the levees , workers closed 111 floodgates . The New Orleans International Airport closed, with jumbo jets being flown to other airports. A total of 250 members of
64512-600: Was part of Africa, it was initially above water, but during the cooler Jurassic Period , the Florida Platform became a shallow marine environment in which sedimentary rocks were deposited. Through the Cretaceous Period , most of Florida remained a tropical sea floor of varying depths. The peninsula has been covered by seawater at least seven times since the bedrock formed. Fluctuating sea levels compressed numerous layers of calcium carbonate , sand, and shells. The resulting permeable limestone formations that developed between 25 million and 70 million years ago created
64768-474: Was revived in the latter part of World War II for the Western Pacific. Formal naming schemes have subsequently been introduced for the North and South Atlantic, Eastern, Central, Western and Southern Pacific basins as well as the Australian region and Indian Ocean. At present, tropical cyclones are officially named by one of twelve meteorological services and retain their names throughout their lifetimes to provide ease of communication between forecasters and
65024-414: Was sent to Miami via HMCS Protecteur to assist American relief teams. In the aftermath of the storm, extensive psychological effects were documented, including increased divorce rates and a spike in post-traumatic stress disorder (PTSD). A panel of psychiatrists and psychologists at the University of Miami agreed that as many as 90% of residents in the worst impacted areas would experience at least
65280-412: Was sporadic, with precipitation reported as far north as Central Florida . Although effects from Andrew were catastrophic, the extent of damage was limited mainly from Kendall to Key Largo due to the small wind field of the storm. The hurricane destroyed 90% of mobile homes in the county, including 99% of mobile homes in Homestead . At the Homestead Air Force Base , most of the 2,000 buildings on
65536-532: Was wrecked. All of Harbour Island , located northeast of Eleuthera, sustained damage, with several small houses destroyed. Overall, news reports indicated severe damage to 36 houses on the island. One person drowned from the storm surge in Eleuthera, and two others died in nearby The Bluff . On New Providence , the hurricane destroyed one house, but caused no major damage in the capital city of Nassau . The Lynden Pindling International Airport near Nassau recorded 61 mm (2.4 in) of precipitation during
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