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103-414: Severe Tropical Cyclone Yasi ( / ˈ j ɑː s iː / ) was a powerful and destructive tropical cyclone that made landfall in northern Queensland , Australia in early 2011, causing major damage to the affected areas. Originating as a tropical low near Fiji on 26 January, the system intensified to tropical cyclone status during the evening of 30 January. Yasi deepened rapidly over the next 24 hours, and
206-473: A Tropical Cyclone Formation Alert . The storm's low-level circulation centre became increasingly defined and convective banding features were apparent along the northern periphery of the depression. It deepened rapidly throughout 30 January, resulting in the JTWC upgrading the system to a tropical storm after data from an ASCAT image depicted winds near gale-force around the storm's centre. Shortly thereafter,
309-518: 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
412-416: 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
515-545: A 10 kilometre backup of traffic. Many of those who evacuated the devastated areas including emergency workers were stranded. On 5 February, the remnants of Yasi as a tropical low created torrential rain as rainfall of 140 mm (5.5 in) was recorded in Terowie and Yongala . Flooding was widespread in towns of northern South Australia reaching even Renmark on the River Murray . In north-west Victoria , Mildura recorded
618-444: 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
721-590: 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
824-405: 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
927-473: A high tide of up to 7 m (23 ft) above average. In Mission Beach near where Cyclone Yasi made landfall, wind gusts were estimated to have reached 290 km/h (180 mph), leaving behind much damage. A storm surge estimated to have reached 7 m (23 ft) destroyed several structures along the coast and pushed up to 300 m (980 ft) inland. In the hours after the storm's passage, police could not venture beyond their station grounds as
1030-506: 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
1133-460: 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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#17328915823331236-464: 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
1339-426: 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
1442-493: 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
1545-479: A pressure of 929 hPa (27.43 inches of mercury ). At the same time, the JTWC estimated Yasi's winds to have topped out at 155 mph (250 kilometres per hour). Traveling southwestwards, Yasi remained a powerful storm until its landfall near Mission Beach, Queensland , at 14:00 UTC on February 2. Upon making landfall, the storm rapidly weakened and was no longer a Severe Tropical cyclone 6 hours after landfall. For
1648-422: 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
1751-538: A record rainfall amount of 98 mm (3.9 in). Damaging winds with gusts of more than 90 km/h hit Marla and Coober Pedy . More than 100 mm (3.9 in) also fell at Arkaroola and Mt Dare, 92 mm (3.6 in) fell at Marree , and 86 mm (3.4 in) at Yunta . Even one week after the flooding rains, areas that were affected had become completely isolated. At Challenger Gold Mine 150 people were isolated and emergency supplies had to be flown in. Cattle Stations near Oodnadatta , Glendambo and
1854-429: 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
1957-548: A result of rough seas. During 28–30 January, Yasi's precursor tropical depression caused rain and strong winds over the Fijian islands off Rotuma , Vanua Levu , Taveuni and the northern Yasawa Islands . During 30 January, Yasi became the second of three systems to directly impact Vanuatu in two months. Tropical Cyclone Yasi moved across Vanuatu's northern Torba Province , with winds reaching up to 95 km/h (60 mph). Vanuatuan officials reported difficulties making contact with
2060-518: A shallow eye developing by 31 January. As the storm continued to intensify, a well defined circular eye developed. The storm reached Category 4 intensity late on 1 February, and Category 5 status early on the next day. Meanwhile, the JTWC assessed the system to have reached Category 4-equivalent status on the Saffir–Simpson scale . Later that day, Yasi reached its peak intensity with 10-minute sustained winds of 125 mph (200 kilometres per hour) and
2163-562: 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
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#17328915823332266-565: 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
2369-405: 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
2472-518: 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,
2575-461: 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
2678-401: 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
2781-476: A tropical low near Mount Isa , at 10 PM on 3 February 2011, 22 hours after the storm first crossed the coast. The storm caused an estimated AU$ 3.5 billion (US$ 3.6 billion) in damage, making it the costliest tropical cyclone to hit Australia on record (not accounting for inflation; otherwise, Cyclone Tracy was costlier). Yasi was also indirectly responsible for the death of a 23-year-old man, who died from suffocation by generator exhaust fumes. Tropical Cyclone Yasi
2884-695: A two-digit number and suffix letter by the warning centers that monitor them. 160th meridian east The meridian 160° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean , Asia , the Pacific Ocean , the Southern Ocean , and Antarctica to the South Pole . The 160th meridian east forms a great circle with the 20th meridian west . In Antarctica ,
2987-813: 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
3090-473: Is a rapidly rotating storm system with 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
3193-683: 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
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3296-415: 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
3399-406: 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
3502-545: 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
3605-414: 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
3708-445: 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
3811-502: 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
3914-405: 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
4017-608: 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
4120-507: 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
4223-618: 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
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4326-559: 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
4429-576: The Royal Australian Air Force and other agencies (such as the Royal Flying Doctor Service ) to Brisbane . The Queensland state emergency coordinator warned residents that they would be on their own for up to 24 hours, as the conditions would be too dangerous for emergency responders. Waves as high as 12 m (39.37 ft) were predicted to hit the north Queensland coast as the storm surge caused by Cyclone Yasi combined with
4532-404: 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
4635-561: 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
4738-455: The Torba Province , but it was believed that the northern area escaped major damage. The storm was several hundred kilometres southeast of Papua New Guinea , but the outer edges of the large system brought strong winds, high seas and heavy rain to the country. In Milne Bay Province , local officials advised residents living along the coast to move to higher grounds. As Yasi moved into
4841-514: 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
4944-621: 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,
5047-528: The Australian region meteorological data from the weather station on Willis Island was used to help monitor the system. Ahead of the system impacting the island, staff battened down the buildings and were evacuated off the island by a helicopter during 1 February. Yasi subsequently passed directly over the weather station during 2 February, where wind gusts of 185 km/h (115 mph) and a minimum pressure of 937.9 hPa (27.70 inHg) were recorded, before
5150-539: 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
5253-554: The FMS also upgraded the storm, classifying it as Tropical Cyclone Yasi. Upon being classified a tropical cyclone, Yasi was located about 370 km (230 mi) northeast of Vanuatu . Along the north edge of a strong subtropical ridge , the storm tracked generally westward, taking it through the northern islands of the country. Continuing to rapidly intensify, Yasi attained severe tropical cyclone intensity with ten-minute sustained winds of at least 120 km/h (75 mph) on 31 January, as
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#17328915823335356-629: 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}
5459-460: 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
5562-585: 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
5665-575: 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
5768-506: The banana crop was destroyed, and damage to the sugar cane farms was expected to cost about AU$ 500 million. Damage to power lines left 150,000 homes without electricity. Tropical Disturbance 09F was first identified on 26 January 2011 by the Fiji Meteorological Service (FMS), while it was 330 km (205 mi) south-southwest of Tuvalu . Over a region of high sea surface temperatures and low to moderate wind shear , it
5871-435: 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
5974-486: 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
6077-469: 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
6180-489: The evening. At about 12:00 AM AEST (14:00 UTC) on 3 February, Yasi crossed the Australian coastline as a Category 5 severe tropical cyclone near Mission Beach , with estimated maximum 3-second gusts of 285 km/h spanning an area from Ingham to Cairns. A record low pressure of 929 hPa (27.43 inHg) was measured as the eye passed over Tully . Due to the size of the system and its strong core, Yasi maintained cyclonic intensity farther inland than normal, finally dissipating into
6283-481: 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
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#17328915823336386-410: 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
6489-453: 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
6592-532: 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
6695-598: The highest daily rainfall total on record, with 142 mm (5.6 in) and Lyndhurst, a suburb of Melbourne recorded 180 mm (7.1 in) of rain in the 24 hours falling up to 9am AEDT (22:00 UTC) on 5 February. On 6 February, the BOM reported that Ex-Tropical Cyclone Yasi was 85 km (53 mi) north of Yulara and that heavy rains continued in the Alice Springs area. The deluge also continued in northern South Australia as vast areas continued to get rain. Hallett had
6798-451: 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),
6901-522: 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
7004-436: The island. However, the radar and life-supporting systems took a bit longer to restore and were subsequently completed by the end of November, before staff returned to the island during December 2011. By the time Yasi crossed into Australian basin, preparations for the storm were under way. Media outlets referred to the storm as "what could be the state's worst cyclone in history". Because of its great size, many feared that
7107-674: 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
7210-404: 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
7313-531: The meteorological equipment and communications failed. After the system passed over the island, it became clear that the strong winds and storm surge had damaged the radar, key observing systems as well as communications, operational and life support infrastructure. It was also noted that the system had altered the shape of the island and cleared most of its vegetation. Most of the automated surface observing systems and communications were subsequently restored and became operational, fifteen days after Yasi had passed over
7416-875: The next several days, the storm meandered as a depression over Australia , before dissipating on February 6. Severe Tropical Cyclone Yasi directly impacted the Solomon Islands, Vanuatu and parts of Australia, while parts of Fiji and Papua New Guinea were indirectly impacted. As a result of the system's impacts, the name Yasi was subsequently retired from the list of South Pacific tropical cyclone names and replaced with Yvonne. Between 23 and 30 January, strong winds and swells were observed in Tuvalu, as Tropical Cyclones Wilma and Yasi developed and passed. These strong winds delayed shipping schedules and affected students studying in Vaitupu and Fiji, and outer islands ran out of fresh supplies as
7519-522: 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
7622-466: 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
7725-440: 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
7828-413: 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
7931-563: The primary convective band wrapped around the storm's centre. Later that day, the storm crossed 160°E , prompting the final advisory from the FMS and the first advisory from the Australian Bureau of Meteorology , as the system crossed into the Australian cyclone basin. Shortly after entering the BoM's area of responsibility, the storm initiated a period of rapid intensification under extremely favorable conditions as it turned southwestward, with
8034-444: 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
8137-492: 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
8240-488: 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
8343-513: 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
8446-692: The situation had yet to be declared safe. Most of the beach had lost its sand and every structure was damaged to some degree. Near sunrise on 3 February, there were no reports of fatalities or injuries in Mission Beach. As the eye of the storm moved over several towns in Queensland, news reporters took the opportunity to give brief damage assessments before the eyewall returned. The worst affected areas were around Tully , Tully Heads, Silkwood, Mission Beach , Innisfail and Cardwell . According to residents in Tully,
8549-504: The sound of glass breaking throughout the night as the storm moved through. In Tully, the high school was destroyed and will need to be rebuilt. Numerous emergency calls were made by residents trapped in their homes near the height of the storm. However, their calls could not be acted upon as conditions were too dangerous for police to travel in. One reported instance was of six people trapped in an apartment complex at Port Hinchinbrook near Cardwell , who could not be evacuated. The building
8652-594: 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
8755-419: 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
8858-483: 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
8961-621: 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
9064-493: The town was "...a scene of mass devastation". An unknown number of homes were completely destroyed as intense winds, estimated at 209 km/h (130 mph), battered the area. Many other homes not destroyed sustained severe facade and or roof damage. As daybreak came, reports from the town stated that about 90% of the structures along the main avenue sustained extensive damage. An evacuation centre in Innisfail began to flood as
9167-400: The tropical cyclone could cause damage more severe than Cyclone Larry in 2006 or Cyclone Tracy , which severely damaged Darwin in 1974. Thousands of residents in the path of the storm were urged to evacuate by Queensland Premier Anna Bligh . Thirty thousand people were evacuated from Cairns , including all patients from Cairns Base Hospital and Cairns Private Hospital who were airlifted by
9270-423: 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
9373-451: 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
9476-402: 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
9579-460: The world's largest at Anna Creek Station were all isolated. The Australian Defence Force (ADF) response was designated Operation Yasi Assist . The ADF established Joint Task Force 664, based at Lavarack Barracks in Townsville and under the command of Brigadier Stuart Smith, for operational command on 2 February 2011. Related tropical cyclones Tropical cyclone A tropical cyclone
9682-435: The worst of Yasi's impacts neared. Evacuees were reportedly hammering boards at the bottom of doors to prevent water from further entering the structure. Additionally, concerns over the building's windows came about as they flexed amidst winds over 200 km/h (120 mph). In Townsville , numerous roofs were torn off buildings and sent hurtling down streets. Many windows are believed to have been broken as residents reported
9785-779: 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
9888-523: 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
9991-425: Was classified as a Category 3 cyclone at about 5 PM AEST (07:00 UTC ) on 31 January 2011. Late on 1 February, the cyclone strengthened to a Category 4 system; then, early on 2 February, the cyclone intensified into a Category 5 Severe Tropical Cyclone. The system had a well-defined eye and continued to track west-southwestward, maintaining a central pressure of 930 hPa (27 inHg) and a Dvorak intensity of T6.5 into
10094-471: Was confirmed to have been lost in agriculture, mining and local government. An additional A$ 1 billion has been lost in the tourism industry. One death was due to carbon monoxide poisoning by exhaust of a portable generator being used in a confined space at Bambaroo near Ingham . Two days after landfall, severe flooding from the rains severed the Bruce Highway between Townsville and Ingham leaving
10197-499: Was expected to intensify gradually as it moved southwest. Little development took place over the following two days, though it was classified as a tropical depression on 27 January. By 28 January, the depression was characterised as a poorly-developed low, with a broad area of rotating, flaring convection . Considerable development took place on the following day, prompting the Joint Typhoon Warning Center (JTWC) to issue
10300-526: Was only 24 hours supply, while the water had run out at Magnetic Island in one day. Fears of total devastation to the banana and sugar cane crops arose as the storm struck land. Initial estimates stated that damage to sugar cane alone could reach A$ 505 million. On 3 February, total losses from the storm were estimated to reach A$ 3.5 billion (US$ 3.54 billion), this makes it the costliest cyclone to ever hit Australia (not accounting for inflation). By 5 February, A$ 2 billion (US$ 2.03 billion)
10403-522: 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
10506-416: Was the biggest storm in Queensland's history, with more than 10,000 people moved from their homes. The storm passed between the two big cities of Cairns and Townsville which only suffered minor damage. Early estimates of damage put the cost at about AU$ 100 million. It did not cause as much damage as government expected, as it missed major cities. It did however destroy 30% of the houses in Tully. At least 75% of
10609-459: Was threatened by Yasi's storm surge which exceeded 3 m (9.8 ft). The group were later reported to be safe. Around 10:30 pm local time on 2 February, Premier Bligh stated that an estimated 90,000 structures, including evacuation centres, were without power. This figure rose to 170,000 by morning and officials stated that some residents may be without power for more than a month. The water-supply system had failed in Townsville and there
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