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| Outline of tropical cyclones |
The main effects of tropical cyclones include heavy rain, strong wind, large storm surges near landfall, and tornadoes. The destruction from a tropical cyclone, such as a hurricane or tropical storm, depends mainly on its intensity, its size, and its location. Tropical cyclones act to remove forest canopy as well as change the landscape near coastal areas, by moving and reshaping sand dunes and causing extensive erosion along the coast. Even well inland, heavy rainfall can lead to mudslides and landslides in mountainous areas. Their effects can be sensed over time by studying the concentration of the Oxygen-18 isotope within caves within the vicinity of cyclones' paths.
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean; in the south Pacific or Indian Ocean, comparable storms are referred to simply as "tropical cyclones" or "severe cyclonic storms".
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystems, as well as water for hydroelectric power plants and crop irrigation.
Wind is the flow of gases on a large scale. On the surface of the Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the Sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space. Winds are commonly classified by their spatial scale, their speed, the types of forces that cause them, the regions in which they occur, and their effect. The strongest observed winds on a planet in the Solar System occur on Neptune and Saturn. Winds have various aspects, an important one being its velocity ; another the density of the gas involved; another its energy content or wind energy. Wind is also a great source of transportation for seeds and small birds; with time things can travel thousands of miles in the wind.
After the cyclone has passed, devastation often continues. Fallen trees can block roads and delay rescues, with medical supplies, or slow the repairs to electrical lines, telephone towers or water pipes, which could put other lives at risk for days or months. Standing water can cause the spread of disease, and transportation or communication infrastructure may have been destroyed, hampering clean-up and rescue efforts. Nearly two million people have died globally due to tropical cyclones. Despite their devastating effects, tropical cyclones are also beneficial, by potentially bringing rain to dry areas and moving heat from the tropics poleward. Out at sea, ships take advantage of their known characteristics by navigating through their weaker, western half.
In meteorology, a cyclone is a large scale air mass that rotates around a strong center of low atmospheric pressure. Cyclones are characterized by inward spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale. Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes and dust devils lie within smaller mesoscale. Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of the tropical upper tropospheric trough during the summer months in the Northern Hemisphere. Cyclones have also been seen on extraterrestrial planets, such as Mars and Neptune. Cyclogenesis is the process of cyclone formation and intensification. Extratropical cyclones begin as waves in large regions of enhanced mid-latitude temperature contrasts called baroclinic zones. These zones contract and form weather fronts as the cyclonic circulation closes and intensifies. Later in their life cycle, extratropical cyclones occlude as cold air masses undercut the warmer air and become cold core systems. A cyclone's track is guided over the course of its 2 to 6 day life cycle by the steering flow of the subtropical jet stream.
PST hazards. PST is an acronym standing for Primary, Secondary and Tertiary. A primary hazard involves destructive winds, debris and storm surge. Secondary hazards include flooding and fires. Tertiary hazards include spikes in prices of food and other necessities, as well as long term hazards like water-borne diseases.
A mature tropical cyclone can release heat at a rate upwards of 6x1014 watts.Tropical cyclones on the open sea cause large waves, heavy rain, and high winds, disrupting international shipping and, at times, causing shipwrecks. Generally, after its passage, a tropical cyclone stirs up ocean water, lowering sea surface temperatures behind it. This cool wake can cause the region to be less favorable for a subsequent tropical cyclone. On rare occasions, tropical cyclones may actually do the opposite. 2005's Hurricane Dennis blew warm water behind it, contributing to the unprecedented intensity of Hurricane Emily, which followed it closely. Hurricanes help to maintain the global heat balance by moving warm, moist tropical air to the mid-latitudes and polar regions and also by influencing ocean heat transport. Were it not for the movement of heat poleward (through other means as well as hurricanes), the tropical regions would be unbearably hot.
The watt is a unit of power. In the International System of Units (SI) it is defined as a derived unit of 1 joule per second, and is used to quantify the rate of energy transfer. In dimensional analysis, power is described by .
A shipwreck is the remains of a ship that has wrecked, which are found either beached on land or sunken to the bottom of a body of water. Shipwrecking may be deliberate or accidental. In January 1999, Angela Croome estimated that there have been about three million shipwrecks worldwide.
Sea surface temperature (SST) is the water temperature close to the ocean's surface. The exact meaning of surface varies according to the measurement method used, but it is between 1 millimetre (0.04 in) and 20 metres (70 ft) below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a short distance of the shore. Localized areas of heavy snow can form in bands downwind of warm water bodies within an otherwise cold air mass. Warm sea surface temperatures are known to be a cause of tropical cyclogenesis over the Earth's oceans. Tropical cyclones can also cause a cool wake, due to turbulent mixing of the upper 30 metres (100 ft) of the ocean. SST changes diurnally, like the air above it, but to a lesser degree. There is less SST variation on breezy days than on calm days. In addition, ocean currents such as the Atlantic Multidecadal Oscillation (AMO), can effect SST's on multi-decadal time scales, a major impact results from the global thermohaline circulation, which affects average SST significantly throughout most of the world's oceans.
Shipwrecks are common with the passage of strong tropical cyclones. Such shipwrecks can change the course of history,as well as influence art and literature. A hurricane led to a victory of the Spanish over the French for control of Fort Caroline, and ultimately the Atlantic coast of North America, in 1565. The Sea Venture was wrecked near Bermuda in 1609 which led to the colonization of Bermuda and provided the inspiration for Shakespeare's The Tempest .
Sea Venture was a seventeenth-century English sailing ship, part of the Third Supply mission to the Jamestown Colony, that was wrecked in Bermuda in 1609. She was the 300 ton purpose-built flagship of the London Company and a highly unusual vessel for her day, given that she was the first single timbered, merchantman built in England, and also the first dedicated emigration ship. Sea Venture's wreck is widely thought to have been the inspiration for Shakespeare's play The Tempest.
William Shakespeare was an English poet, playwright and actor, widely regarded as the greatest writer in the English language and the world's greatest dramatist. He is often called England's national poet and the "Bard of Avon". His extant works, including collaborations, consist of approximately 39 plays, 154 sonnets, two long narrative poems, and a few other verses, some of uncertain authorship. His plays have been translated into every major living language and are performed more often than those of any other playwright.
Mariners have a way to safely navigate around tropical cyclones. They split tropical cyclones in two, based on their direction of motion, and maneuver to avoid the right segment of the cyclone in the Northern Hemisphere (the left segment in the Southern Hemisphere). Sailors term the right side the dangerous semicircle since the heaviest rain and strongest winds and seas were located in this half of the storm, as the cyclone's translation speed and its rotational wind are additive. The other half of the tropical cyclone is called the navigable semicirclesince weather conditions are lessened (subtractive) in this portion of the storm (but are still potentially quite hazardous). The rules of thumb for ship travel when a tropical cyclone is in their vicinity are to avoid them if at all possible and do not cross their forecast path (crossing the T). Those traveling through the dangerous semicircle are advised to keep to the true wind on the starboard bow and make as much headway as possible. Ships moving through the navigable semicircle are advised to keep the true wind on the starboard quarter while making as much headway as possible.
The most significant effects of a tropical cyclone occur when they cross coastlines, making landfall then it destroys ships and lives.
Strong winds can damage or destroy vehicles, buildings, bridges, trees, personal property and other outside objects, turning loose debris into deadly flying projectiles. In the United States, major hurricanes comprise just 21% of all land-falling tropical cyclones, but account for 83% of all damage.Tropical cyclones often knock out power to tens or hundreds of thousands of people, preventing vital communication and hampering rescue efforts. Tropical cyclones often destroy key bridges, overpasses, and roads, complicating efforts to transport food, clean water, and medicine to the areas that need it. Furthermore, the damage caused by tropical cyclones to buildings and dwellings can result in economic damage to a region, and to a diaspora of the population of the region.
The storm surge, or the increase in sea level due to the cyclone, is typically the worst effect from landfalling tropical cyclones, historically resulting in 90% of tropical cyclone deaths.The relatively quick surge in sea level can move miles/kilometers inland, flooding homes and cutting off escape routes. The storm surges and winds of hurricanes may be destructive to human-made structures, but they also stir up the waters of coastal estuaries, which are typically important fish-breeding locales.
The thunderstorm activity in a tropical cyclone produces intense rainfall, potentially resulting in flooding, mudslides, and landslides. Inland areas are particularly vulnerable to freshwater flooding, due to residents not preparing adequately.Heavy inland rainfall eventually flows into coastal estuaries, damaging marine life in coastal estuaries. The wet environment in the aftermath of a tropical cyclone, combined with the destruction of sanitation facilities and a warm tropical climate, can induce epidemics of disease which claim lives long after the storm passes. Infections of cuts and bruises can be greatly amplified by wading in sewage-polluted water. Large areas of standing water caused by flooding also contribute to mosquito-borne illnesses. Furthermore, crowded evacuees in shelters increase the risk of disease propagation.
Although cyclones take an enormous toll in lives and personal property, they may be important factors in the precipitation regimes of places they affect and bring much-needed precipitation to otherwise dry regions. Hurricanes in the eastern north Pacific often supply moisture to the Southwestern United States and parts of Mexico. people and caused $9.14 billion (2005 USD) in damage.Japan receives over half of its rainfall from typhoons. Hurricane Camille (1969) averted drought conditions and ended water deficits along much of its path, though it also killed 259
On the other hand, the occurrence of tropical cyclones can cause tremendous variability in rainfall over the areas they affect: indeed cyclones are the primary cause of the most extreme rainfall variability in the world, as observed in places such as Onslow and Port Hedland in subtropical Australia where the annual rainfall can range from practically nothing with no cyclones to over 1,000 millimetres (39 in) if cyclones are abundant.
The broad rotation of a land-falling tropical cyclone often spawns tornadoes, particularly in their right front quadrant. While these tornadoes are normally not as strong as their non-tropical counterparts, heavy damage or loss of life can still occur. Tornadoes can also be spawned as a result of eyewall mesovortices, which persist until landfall.
|Deaths per year from tropical cyclones|
During the last two centuries, tropical cyclones have been responsible for the deaths of about 1.9 million people worldwide. It is estimated that 10,000 people per year perish due to tropical cyclones. The deadliest tropical cyclone was the 1970 Bhola cyclone, which had a death toll of anywhere from 300,000 to 500,000 lives.
Before Hurricane Katrina, which combined storm-tide flooding with levee-breach (dam) flooding from Lake Ponchartrain, the average death rate for tropical cyclones in the United States had been decreasing. The main cause of storm-related fatalities had been shifting away from storm surge and towards freshwater (rain) flooding.However, the median death rate per storm had increased through 1979, with a lull during the 1980–1995 period. This was due to greater numbers of people moving to the coastal margins and into harm's way. Despite advances in warning strategies and reduction in track forecast error, this increase in fatalities is expected to continue for as long as people migrate towards the shore.
While tropical cyclones may well seriously damage settlement, total destruction encourages rebuilding. For example, the destruction wrought by Hurricane Camille on the Gulf coast spurred redevelopment, greatly increasing local property values.Research indicates that the typical hurricane strike raises real house prices by a few percent for a number of years, with a maximum effect of between 3 percent to 4 percent three years after occurrence. However, disaster response officials point out that redevelopment encourages more people to live in clearly dangerous areas subject to future deadly storms. Hurricane Katrina is the most obvious example, as it devastated the region that had been revitalized after Hurricane Camille. Many former residents and businesses do relocate to inland areas away from the threat of future hurricanes as well.
In isolated areas with small populations, tropical cyclones may cause enough casualties to contribute to the founder's effect as survivors repopulate their place. For example, around 1775, a typhoon hit Pingelap Atoll, and in combination with a subsequent famine, reduced the island's population to a low level. Several generations after the disaster, as many as 10% of Pingelapese have a genetic form of color-blindness called achromatopsia.This is due to one of the survivors of the depopulation brought on by the typhoon having a mutated gene, which the population bottleneck caused to be at a higher-than-usual level in succeeding generations.
Tropical cyclones reshape the geology near the coast by eroding sand from the beach as well as offshore, rearranging coral, and changing dune configuration onshore. Their rain water gets absorbed into stalagmites within caves, creating a record of past tropical cyclone impacts.
Waves and storm surges accompanying tropical cyclonesundersea sands, erode shell deposits, break off corals from near shore reefs in their paths, and carry all this detritus landwards in a rolling wave of material that is deposited onshore, above highest astronomical tide as a ridge of sand, shell and coral. 4–5 on the Saffir-Simpson scale) crossing northeast Australia's tropical coastline since the last significant change in sea levels (about 5,000 years ago) has 'emplaced' such ridges within the coastal landscape forming, in some places, series of ridges and a geomorphological record of highest magnitude cyclones hitting the coast over 3,000–5,000 years.For example, each severe tropical cyclone (i.e. Category
Eyewitness accounts verify ridges of this kind are formed by severe tropical cyclones and two clear examples cited are the 18 kilometres (11 mi) long, 35 metres (115 ft) wide, 3.5 metres (11 ft) high coral shingle ridge deposited on Funafuti Atoll (Central South Pacific) by Cyclone Bebe in October 1972, and the large coral shingle ridge deposited on Jaluit Atoll (Marshall Islands) by Typhoon Ophelia in January 1958. In tropical northeast Australia, an intense tropical cyclone hit in March 1918 (crossing over the town of Innisfail), at which time there were eyewitness accounts of a 4.5 metres (15 ft) to 5.1 metres (17 ft) high ridge of pumice being deposited by that cyclone's surge as it crossed the coast.).
When tropical cyclones cross land, thin layers of calcium carbonate of 'light' composition (i.e. unusual isotopic ratio of Oxygen-18 and Oxygen-16) are deposited onto stalagmites in limestone caves up to 300 kilometres (190 mi) from the cyclone's path.
As the cloud tops of tropical cyclones are high and cold, and their air is humid – their rainwater is 'lighter'. In other words, the rainfall contains significantly higher quantities of unevaporated Oxygen-18 than other tropical rainfall. The isotopically lighter rainwater soaks into the ground, percolates down into caves, and, within a couple of weeks, Oxygen-18 transfers from the water into calcium carbonate, before being deposited in thin layers or 'rings' within stalagmites. A succession of such events created within stalagmites maintain a record of cyclones tracking within a 300 kilometres (190 mi) radius of caves going back centuries, millennia, or even millions of years.
At Actun Tunichil Muknal cave in central Belize, researchers drilling stalagmites with a computer- controlled dental drill accurately identified and verified evidence of isotopically light rainfall for 11 tropical cyclones occurring over a 23-year period (1978–2001).
At the Chillagoe limestone caves in northeast Australia (130 kilometres (81 mi) inland from Cairns) researchers identified and matched evidence of isotopically light rainfall with 100 years of cyclone records, and from this have created a record of tropical cyclones from 2004 back to 1200 A.D. (an 800-year record).
Severe tropical cyclones defoliate tropical forest canopy trees, remove vines and epiphytes from the trees, break tree crown stems, and cause tree falls. The degree of damage they do along their paths, at a landscape level (i.e. > 10 kilometres (6.2 mi)), can be catastrophic yet variable and patchy. Trees will break at 42 m/s (150 km/h; 94 mph), regardless of size and type. Stripping trees and scattering forest debris also provides fuel for wildfires, such as a blaze that lasted three months in 1989 and burned 460 square miles (1,200 km2) of forest that had been stripped by Hurricane Gilbert.
Assessments of cyclone damage done to tropical rainforest landscapes in northeast Australia, have produced the following typology for describing and 'mapping' the variable impacts they have along their paths, as follows:
A storm is any disturbed state of an environment or in an astronomical body's atmosphere especially affecting its surface, and strongly implying severe weather. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning, heavy precipitation, heavy freezing rain, strong winds, or wind transporting some substance through the atmosphere as in a dust storm, blizzard, sandstorm, etc.
The Saffir–Simpson hurricane wind scale (SSHWS), formerly the Saffir–Simpson hurricane scale (SSHS), classifies hurricanes – Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms – into five categories distinguished by the intensities of their sustained winds.
Hurricane Opal was a large and powerful Category 4 hurricane that caused severe and extensive damage along the northern Gulf Coast of the United States in October 1995. The ninth hurricane and strongest tropical cyclone of the unusually active 1995 Atlantic hurricane season, Opal developed from the interaction of a tropical wave and a low-pressure area near the Yucatán Peninsula on September 27. It then crossed the Yucatán Peninsula while still a tropical depression and intensified into a tropical storm on September 30. After entering the Gulf of Mexico and then becoming a hurricane on October 2, Opal turned northeastward and strengthened significantly. By October 4, Opal was an intense 150 mph (240 km/h), Category 4 hurricane. However, the cyclone abruptly weakened to a low-end Category 3 hurricane prior to making landfall in the Florida Panhandle near Pensacola later that day. The storm quickly weakened inland and became extratropical on October 5. The remnants of Opal persisted until dissipating over Ontario by the following day.
The 1938 New England Hurricane was one of the deadliest and most destructive tropical cyclones to strike Long Island, New York and New England. The storm formed near the coast of Africa on September 9, becoming a Category 5 hurricane on the Saffir-Simpson Hurricane Scale before making landfall as a Category 3 hurricane on Long Island on September 21. It is estimated that the hurricane killed 682 people, damaged or destroyed more than 57,000 homes, and caused property losses estimated at $306 million. Damaged trees and buildings were still seen in the affected areas as late as 1951. It remains the most powerful and deadliest hurricane in recorded New England history, perhaps eclipsed in landfall intensity only by the Great Colonial Hurricane of 1635.
A mesoscale convective system (MCS) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones, and normally persists for several hours or more. A mesoscale convective system's overall cloud and precipitation pattern may be round or linear in shape, and include weather systems such as tropical cyclones, squall lines, lake-effect snow events, polar lows, and Mesoscale Convective Complexes (MCCs), and generally form near weather fronts. The type that forms during the warm season over land has been noted across North America, Europe, and Asia, with a maximum in activity noted during the late afternoon and evening hours.
Typhoon Vera, also known as the Isewan Typhoon, was an exceptionally intense tropical cyclone that struck Japan in September 1959, becoming the strongest and deadliest typhoon on record to make landfall on the country. The storm's intensity resulted in damage of unparalleled severity and extent, and was a major setback to the Japanese economy, which was still recovering from World War II. In the aftermath of Vera, Japan's disaster management and relief systems were significantly reformed, and the typhoon's effects would set a benchmark for future storms striking the country.
The years before 1975 featured the pre-1975 North Indian Ocean cyclone seasons. Each season was an ongoing event in the annual cycle of tropical cyclone formation. The North Indian tropical cyclone season has no bounds, but they tend to form between April and December, peaks in May and November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean. Below are the most significant cyclones in the time period. Because much of the North Indian coastline is near sea level and prone to flooding, these cyclones can easily kill many with storm surge and flooding. These cyclones are among the deadliest on earth in terms of numbers killed.
Tropical Storm Arlene was an unusually large and early-forming tropical storm, being the first of twenty-eight different storms during the 2005 Atlantic hurricane season, which would become the most active season on record. Tropical Storm Arlene formed near Honduras on June 8 and moved northwards. It crossed western Cuba on June 10 and strengthened to just under hurricane strength before making its final landfall on the Florida Panhandle the next day. The storm weakened as it continued to move north over the United States, becoming extratropical on June 13. Arlene was responsible for only one death and minor damages.
Hurricane Danny produced 13 significant (F2/EF2+) tornadoes in the Southern United States during August 1985, the most spawned by a tropical cyclone until Hurricane Ivan in 2004. The fourth named storm and third hurricane of the season, Danny developed from a tropical wave in the northwestern Caribbean Sea on August 12. The system moved northwestward and initially remained weak. Early on August 13, it brushed Cape San Antonio, Cuba before emerging the Gulf of Mexico later that day. The system then intensified into Tropical Storm Danny on August 14. Danny deepened further and became a hurricane early on the following day, while beginning to re-curve north-northwestward. Late on August 16, Danny attained its peak intensity with winds of 90 mph (150 km/h). Shortly thereafter, the storm made landfall near Grand Chenier, Louisiana at the same intensity. Early on August 17, Danny weakened to a tropical storm and was downgraded to a tropical depression several hours later. It moved east-northeastward across the Southeastern United States, until dissipating over southeastern Virginia on August 18.
Hurricane Audrey was one of the deadliest tropical cyclones in U.S. history, as well as the strongest June hurricane ever recorded in the Atlantic basin, tied with Hurricane Alex in 2010. The rapidly developing storm struck southwestern Louisiana as a powerful Category 3 hurricane, destroying coastal communities with a powerful storm surge that penetrated as far as 20 mi (32 km) inland. The first named storm and hurricane of the annual hurricane season, it formed on June 24 from a tropical wave which moved into the Bay of Campeche. Situated within ideal conditions for tropical development, Audrey quickly strengthened, reaching hurricane status a day afterwards. Moving northwards, it continued to strengthen and accelerate as it approached the United States Gulf Coast. On June 27, the hurricane reached peak sustained winds of 125 mph (205 km/h), making it a major hurricane. At the time, Audrey had a minimum barometric pressure of 946 mbar. The hurricane made landfall at the same intensity between the mouth of the Sabine River and Cameron, Louisiana later that day, causing unprecedented destruction across the region. Once inland, Audrey weakened and turned extratropical over West Virginia on June 29.
Tropical Storm Bill was a tropical storm that affected the Gulf Coast of the United States in the summer of 2003. The second storm of the 2003 Atlantic hurricane season, Bill developed from a tropical wave on June 29 to the north of the Yucatán Peninsula. It slowly organized as it moved northward, and reached a peak of 60 miles per hour (97 km/h) shortly before making landfall in south-central Louisiana. Bill quickly weakened over land, and as it accelerated to the northeast, moisture from the storm, combined with cold air from an approaching cold front, produced an outbreak of 34 tornadoes. Bill became extratropical on July 2, and was absorbed by the cold front later that day.
Landfall is the event of a storm or waterspout moving over land after being over water.
Tropical Storm Alberto was the first tropical storm of the 2006 Atlantic hurricane season. Forming on June 10 in the northwestern Caribbean, the storm moved generally to the north, reaching a maximum intensity of 70 mph (110 km/h) before weakening and moving ashore in the Big Bend area of Florida on June 13. Alberto then moved through eastern Georgia, North Carolina, and Virginia as a tropical depression before becoming extratropical on June 14.
Tropical cyclone observation has been carried out over the past couple of centuries in various ways. The passage of typhoons, hurricanes, as well as other tropical cyclones have been detected by word of mouth from sailors recently coming to port or by radio transmissions from ships at sea, from sediment deposits in near shore estuaries, to the wiping out of cities near the coastline. Since World War II, advances in technology have included using planes to survey the ocean basins, satellites to monitor the world's oceans from outer space using a variety of methods, radars to monitor their progress near the coastline, and recently the introduction of unmanned aerial vehicles to penetrate storms. Recent studies have concentrated on studying hurricane impacts lying within rocks or near shore lake sediments, which are branches of a new field known as paleotempestology. This article details the various methods employed in the creation of the hurricane database, as well as reconstructions necessary for reanalysis of past storms used in projects such as the Atlantic hurricane reanalysis.
Severe weather refers to any dangerous meteorological phenomena with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, altitude, topography, and atmospheric conditions. High winds, hail, excessive precipitation, and wildfires are forms and effects of severe weather, as are thunderstorms, downbursts, tornadoes, waterspouts, tropical cyclones, and extratropical cyclones. Regional and seasonal severe weather phenomena include blizzards (snowstorms), ice storms, and duststorms.
Hurricane Humberto was a Category 1 hurricane that formed and intensified faster than any other North Atlantic tropical cyclone on record, before landfall. Developing on September 12, 2007, in the northwestern Gulf of Mexico, the tropical cyclone rapidly strengthened and struck High Island, Texas, with winds of about 90 mph (150 km/h) early on September 13. It steadily weakened after moving ashore, and on September 14, Humberto began dissipating over northwestern Georgia as it interacted with an approaching cold front.
Tropical Storm Bill was a tropical cyclone that produced widespread rainfall across East Texas, Oklahoma, the Midwest, and Mid-Atlantic. The second named storm of the season, Bill developed from a broad area of low pressure over the northwestern Gulf of Mexico on June 16. Because the system was already producing tropical storm force winds, it was immediately classified as Tropical Storm Bill. Initially continuing northwestward, Bill re-curved west-northwestward later on June 16. Around 12:00 UTC, the storm peaked with maximum sustained winds of 60 mph (95 km/h). Just under five hours later, Bill made landfall near on Matagorda Island, Texas, at the same intensity. The cyclone weakened to a tropical depression and turned northward early on June 17. Bill remained a tropical cyclone until late on June 18, when it degenerated into a remnant low. The remnant low moved east-northeastward until dissipating over West Virginia on June 21.