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127-406: In the present, Guangnan County has 7 towns and 11 townships. Guangnan, as with much of southern Yunnan, has a warm humid subtropical climate ( Köppen Cwa ), with muddled distinction between the seasons and daytime temperatures remaining warm year-round. The warmest and coolest months are July and January, respectively at 23.2 °C (73.8 °F) and 9.1 °C (48.4 °F); the annual mean

254-552: A Cfb / Cfa ( Oceanic climate / Humid subtropical climate ) borderline case. Western Georgia ( Batumi and Kutaisi ) in the Kolkheti Lowland and the northeast coast of Turkey ( Giresun ), have a climate similar to that of Gilan and Mazandaran in Iran and very similar to that of southeastern and northern Azerbaijan. Temperatures range from 22 °C (72 °F) in summer to 5 °C (41 °F) in winter and rainfall

381-531: 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

508-416: 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

635-444: 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

762-613: 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

889-405: 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

1016-506: 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

1143-500: A highly pronounced summer peak, unlike other regions of this climate type. Drought can be severe and often catastrophic to agriculture in the Cwa zone. The only area where winter precipitation equals or even exceeds the summer rain is around the San'in region at the western coast of Japan, which during winter is on the windward side of the westerlies. The winter precipitation in these regions

1270-782: A humid subtropical climate with a distinctively high amount of rainfall during summer. In France, the climate is found in parts of the Garonne Valley (city of Toulouse ) and in the Rhône Valley , including the cities of Lyon and Valence . Due to climate change, some cities on the Balkan peninsula and in the Pannonian Basin such as Belgrade , Novi Sad , Niš and Budapest are now just warm enough to be categorized as such. At 48°N , Bratislava , in Slovakia , lies on

1397-518: A humid subtropical climate, generally in the form of hot and humid summers, and mild to cool winters. These areas, which include the Pampas , generally feature a Cfa climate categorization. At 38°S , the Argentine city of Bahía Blanca lies on the southern limit of the humid subtropical zone. The Cwa climate occurs in parts of tropical highlands of São Paulo state , Mato Grosso do Sul and near

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1524-464: 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

1651-464: 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

1778-520: A mean temperature above 10 °C (50 °F). While many subtropical climates tend to be located at or near coastal locations, in some cases, they extend inland, most notably in China and the United States , where they exhibit more pronounced seasonal variations and sharper contrasts between summer and winter, as part of a gradient between the hotter tropical climates of the southern coasts and

1905-465: A more humid July. This is followed by the cooler but still hot and extremely humid monsoon season (August-September), where the region experiences heavy rains almost daily, with humidity usually above 90%. The autumn season (October-November), which immediately follows the monsoon and precedes winter, usually experiences a pleasant climate. Cities such as New Delhi , Dehradun , Lucknow , Kanpur and Patna , among others, exhibit this atypical version of

2032-426: 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

2159-493: 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

2286-422: 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

2413-429: 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

2540-478: A result of these systems. As an example Lismore which lies in the centre of this zone, the annual rainfall can range from less than 550 millimetres (22 in) in 1915 to more than 2,780 millimetres (109 in) in 1950. As the continent does not have a large ocean to its east as the case in many other continents within the climate zone, humid subtropical climates in Europe are limited to relatively small areas on

2667-526: 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 is a strong tropical cyclone that occurs in the Atlantic Ocean or northeastern Pacific Ocean . A typhoon occurs in

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2794-569: 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

2921-581: 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

3048-491: A summer peak especially where storms reaching the level of monsoons are well developed, as in Southeast Asia and South Asia . Other areas have a more uniform or varying rainfall cycles but consistently lack any predictably dry summer months unlike Mediterranean climates (which lie at similar latitudes but, in most continents, on opposite coasts). Most summer rainfall occurs during thunderstorms that build up due to

3175-405: 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

3302-453: A tendency toward dry conditions in winter with rain increasing in spring, with December or January often the driest months. Humid subtropical climates are found in a sizable portion of South America. The climate extends over a few states of southern Brazil, including Paraná , into sections of Paraguay , all of Uruguay and central Argentina (Pampas region). Major cities such as São Paulo , Buenos Aires , Porto Alegre and Montevideo , have

3429-529: 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,

3556-461: 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

3683-401: 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

3810-538: A tropical savanna, or Aw , climate. Annual rainfall within Australia's humid subtropical climate zone can reach as high as 2,000 millimetres (79 in) in coastal locations and is generally 1,000 millimetres (39 in) or above. The most intense 2-3 day rainfall periods that occur in this coastal zone however are the outcome of east coast lows forming to the north of a large high pressure system , there can be great variation in rainfall amounts from year to year as

3937-831: 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

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4064-684: Is 17.4 °C (63.3 °F). May thru September accounts for nearly 75% of the annual rainfall of 1,016 mm (40 in) The following information in this section is from the Guangnan County Gazetteer ( 广南县志 ) (2001). Ethnic Zhuang and Han make up about 80% of the county's population, with each group making up about 40%. There were 81,223 ethnic Miao individuals comprising 16,086 households as of 1995. There were 14,707 ethnic Yao individuals comprising 2,673 households as of 1995. There were 35,879 ethnic Yi individuals comprising 7,001 households as of 1995, making up 5.21% of

4191-471: Is a temperate climate type characterized by hot and humid summers, and cool to mild winters. These climates normally lie on the southeast side of all continents (except Antarctica), generally between latitudes 25° and 40° and are located poleward from adjacent tropical climates, and equatorward from either humid continental (in North America and Asia) or oceanic climates (in other continents). It

4318-567: Is also found in the narrow coastal sections of southern and eastern South Africa , primarily in KwaZulu-Natal and the Eastern Cape provinces. South Africa's version of this climate features heavy oceanic influences resulting in generally milder temperatures. This is particularly evident in its winters when temperatures do not drop as low as in many other regions within the humid subtropical category. In East Asia , this climate type

4445-452: Is also known as warm temperate climate in some climate classifications. Under the Köppen climate classification , Cfa and Cwa climates are either described as humid subtropical climates or warm temperate climates. This climate features mean temperature in the coldest month between 0 °C (32 °F) (or −3 °C (27 °F)) and 18 °C (64 °F) and mean temperature in

4572-415: 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

4699-406: 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

4826-554: 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

4953-414: 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

5080-642: Is even heavier than in Caspian Iran, up to 2,300 millimetres (91 in) per year in Hopa (Turkey). These climates are a Cfb / Cfa ( Oceanic climate / Humid subtropical climate ) borderline case. In North America, humid subtropical climates are found in the American Gulf and lower East Coast states, including Alabama , Arkansas , Florida , Georgia , Louisiana , Mississippi , North Carolina , Oklahoma , South Carolina , Tennessee , and Texas . On

5207-477: Is found in the southeastern quarter of mainland China from Hong Kong north to Nanjing, the northern half of Taiwan , southern and central Japan ( Kyushu , Shikoku and half of Honshu ), and the most southern regions of Korea (the south and east Central and Southern Gyeongsang Province and Jeju island ). Cities near the equatorward boundary of this zone include Hong Kong and Taipei ; while Tokyo , Busan - Pohang - Gangneung of Korea and Qingdao are near

Guangnan County - Misplaced Pages Continue

5334-677: Is generally not as high here as in other continents within this climatic zone. The Po Valley , in Northern Italy , including major cities such as Milan , Turin , Bologna , and Verona , has a humid subtropical climate, featuring hot, humid summers with frequent thunderstorms; winters are foggy, damp and chilly, with sudden bursts of frost. Places along the shores of Lake Maggiore , Lake Lugano , Lake Como ( Como and Verbania in Italy and Lugano and Locarno in Switzerland ) have

5461-491: Is plentiful in North America's humid subtropical climate zone – but with significant variations in terms of wettest/driest months and seasons. Much of the interior South , including Tennessee, Kentucky, and the northern halves of Mississippi and Alabama, tends to have a winter or spring (not summer) precipitation maximum. Closer to the South Atlantic and Gulf coasts, there is a summer maximum, with July or August usually

5588-445: 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

5715-512: 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

5842-405: 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

5969-652: Is usually produced by low-pressure systems off the east coast that develop in the onshore flow from the Siberian high. Summer rainfall comes from the East Asian Monsoon and from frequent typhoons . Annual rainfall is generally over 1,000 millimetres (39 in), and in areas below the Himalayas can be much higher still. Humid subtropical climates can also be found in the Indian subcontinent , predominantly in

6096-464: Is usually three inches or less. However, for the majority of the winter here, temperatures remain above or well above freezing. At the northernmost limits of this zone, cities such as New York City , Philadelphia , Baltimore , Washington, D.C. , and Louisville typically see snowfall during the winter, with occasional heavy snowstorms. Still, average temperatures during a typical winter hover just above freezing at these locations. Precipitation

6223-620: 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

6350-453: The Andean highland in northwestern Argentina . These highland areas feature summer temperatures that are warm enough to fall outside the subtropical highland climate category. The humid subtropical climate zone predominantly lies in eastern Australia, which begins from the coastal strip of Mackay, Queensland and stretches down the coast to just south of Sydney , where it transitions into

6477-573: 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

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6604-828: The Caucasus , in Azerbaijan and in Georgia wedged between the Caspian and Black seas and coastal ( Black Sea ) Turkey, albeit having more oceanic influence. Annual rainfall ranges from around 600 millimetres (24 in) at Gorgan to over 1,830 millimetres (72 in) at Bandar-e Anzali , and is heavy throughout the year, with a maximum in October or November when Bandar-e Anzali can average 330 millimetres (13 in) in one month. Temperatures are generally moderate in comparison with other parts of Western Asia. During winter,

6731-455: The Holdridge life zones classification, the subtropical climates have a biotemperature between the frost or critical temperature line, 16 to 18 °C (61 to 64 °F) (depending on locations in the world) and 24 °C (75 °F), and these climates are humid (or even perhumid or superhumid) when the potential evapotranspiration (PET) ratio (= PET / Precipitation) is less than 1. In

6858-647: 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

6985-778: The Kashmir Valley in India, where the primary precipitation peak occurs in March, not July or August). Further east, in highland areas with lengthier monsoons such as Nepal, seasonal temperature variation is lower than in the lowlands. In Southeast Asia , about 90% of the region has a tropical climate ; but humid subtropical climates can also be seen here, such as in Northern Vietnam (including Hanoi ). Southeast Asian locations with these climates can feature cool temperatures, with lows reaching 10 °C (50 °F) during

7112-559: 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

7239-460: 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

7366-575: 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

7493-668: The humid continental zone due to colder winters. All these areas are subject to occasional, in some cases repeated snowfalls and freezes during winter. In Central Europe , a small area of humid subtropical climates are located in transitional areas between the oceanic and continental climates in areas where higher summer temperatures do not quite qualify it for inclusion in the Oceanic climate schema and mild winters do not allow their inclusion into continental climates. Average summer temperatures in areas of Europe with this climate are generally not as hot as most other subtropical zones around

7620-514: 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

7747-640: 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,

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7874-556: 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

8001-576: The Florida peninsula, the humid subtropical climate gives way to the tropical climate of South Florida and the Florida Keys . Under Köppen's climate classification, this zone includes locations further north, primarily Virginia , Kentucky , the lower elevations of West Virginia , Maryland , Delaware , Washington, D.C. , southeastern Pennsylvania , central and southern portions of New Jersey , and Downstate New York . It can also be found in

8128-540: The Gulf of Mexico, such as Austin and San Antonio that border the semi-arid climate zone, generally see a peak of precipitation in May, a drought-like nadir in mid-summer and a secondary, if not equal, precipitation peak in September or October. Areas further south along South Texas ' Gulf Coast (Brownsville), which closely border tropical climate classification , typically have a strong September precipitation maximum, and

8255-478: The Holdridge classification, the humid subtropical climates coincide more or less with the warmest Cfa and Cwa climates and the less warm humid tropical "Köppen" climates ( Aw , Am and Af ). Cfa : C = Mild temperate f = Fully humid a = Hot Summer Cwa : C = Mild temperate w = Dry Winter a = Hot Summer In Africa, humid subtropical climates are primarily found in

8382-501: The Köppen, most of these locations would not be included in the humid subtropical grouping. The higher summer precipitation and poleward flow of tropical air-masses in summer are not present in Europe as they are in eastern Australia or the southern United States. Tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure center, a closed low-level atmospheric circulation , strong winds, and

8509-594: The Nepalese version of the climate generally does not feature the extreme hot spells that are commonplace for many other South Asian locations with this climate. In Nepal cities such as Kathmandu , Pokhara , Butwal , Birgunj and Biratnagar feature this iteration of the climate. In South Asia, humid subtropical climates generally border on continental climates as altitude increases, or on winter-rainfall climates in western areas of Pakistan and northwestern India (e.g. Peshawar in northwestern Pakistan or Srinagar in

8636-632: 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}

8763-463: 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

8890-688: The Sydney region ranges between 800 and 1,200 millimetres (31 and 47 in). There is usually a distinct summer rainfall maximum that becomes more pronounced moving northwards. In Brisbane, the wettest month (February) receives five times the rainfall of the driest month (September). Temperatures are very warm to hot but are not excessive: the average maximum in February is usually around 29 °C (84 °F) and in July around 21 °C (70 °F). Frosts are extremely rare except at higher elevations, but temperatures over 35 °C (95 °F) are not common on

9017-610: 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

9144-591: 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

9271-464: The climate in India. In Pakistan, the cities of Islamabad , Sialkot , Gujranwala and Rawalpindi , among others, feature this weather pattern. Lahore overlaps between being humid subtropical and semi-arid . The annual precipitation in Peshawar is slightly less than required for this classification. In Bangladesh , cities like Rangpur , Saidpur and Dinajpur in the northern region feature

9398-589: The coast. North of the Cfa climate zone there is a zone centred upon Rockhampton which extends north to the Köppen Cwa classified climate zone of the Atherton Tablelands region. This region has a very pronounced dry winter period, with often negligible rainfall between June and October. Winter temperatures generally only fall slightly below 18 °C (64 °F), which would classify the region as

9525-612: The coastal areas can receive snowfall, which is usually of a short duration. In Rasht , the average temperature in July and August is around 25 °C (77 °F) but with near-saturation humidity , whilst in January and February it is around 7 °C (45 °F). The heavy, evenly distributed rainfall extends north into the Caspian coastal strip of Azerbaijan up to its northern border but this climate in Azerbaijan is, however,

9652-537: The colder continental climates to the north and further inland. As such, the climate can be said to exhibit somewhat different features depending on whether it is found inland, or in a maritime position. In a humid subtropical climate, summers are typically long, hot and humid. A deep current of tropical air dominates the humid subtropics at the time of high sun, and daily intense (but brief) convective thundershowers are common. Monthly mean temperatures in winter may be mild or slightly above freezing. Rainfall often shows

9779-557: The coldest limit of climates classed as humid subtropical. Snowfall varies greatly in this climate zone. In locations at the southern limits of this zone and areas around the Gulf Coast , cities such as Orlando , Tampa , Houston , New Orleans , and Savannah rarely see snowfall, which occurs, at most, a few times per generation. In Southern cities farther north or inland, such as Atlanta , Charlotte , Dallas , Memphis , Nashville , and Raleigh , snow only occasionally falls and

9906-499: The cooler, oceanic climates. From Newcastle , approximately 200 kilometres (120 mi) northeast of Sydney, the Cfa zone would extend to inland New South Wales , excluding the highland regions (which have an oceanic climate), stretching towards Dubbo to the northwest and Wagga Wagga to the south, ending at the New South Wales / Victoria border ( Albury-Wodonga ). To note, these places would have characteristics of

10033-524: The county's total population. There are 157 ethnic Gelao. There were 1,306 ethnic Hui individuals comprising 314 households as of 1995. Most lived in Zhulin Township, which had 964 ethnic Hui individuals comprising 212 households. Liancheng Township, the county seat, had 161 ethnic Hui individuals comprising 51 households. There are 497 ethnic Mongols. Historical villages include: Humid subtropical climate A humid subtropical climate

10160-435: 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

10287-492: 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

10414-469: 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

10541-481: 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

10668-410: 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

10795-453: 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

10922-532: 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

11049-511: The high elevations of Trans-Mexican Volcanic Belt and Sierra Madre Oriental. Despite being located at higher elevations, these locations have summers that are too warm to qualify as a subtropical highland climate. Guadalajara 's climate is a major example of this. Outside of isolated sections of Mexico, the southernmost limits of this climate zone in North America lie just north of South Florida and around southern coastal Texas. Cities at

11176-432: The intense surface heating and strong subtropical sun angle. Weak tropical lows that move in from adjacent warm tropical oceans, as well as occasional tropical cyclones often contribute to summer seasonal rainfall peaks. Winter rainfall (and occasional snowfall, especially near the poleward margins) is often associated with large storms in the westerlies that have fronts that reach down into subtropical latitudes. Under

11303-451: 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),

11430-522: 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

11557-693: 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

11684-454: The lower Midwest, primarily in the central and southern portions of Kansas and Missouri and the southern portions of Illinois , Indiana and Ohio . In Mexico , there are small areas of Cfa and Cwa climates. The climate can be found in small areas scattered around the northeastern part of the country, in proximity to the Gulf of Mexico . Other areas where the climate can be found is in

11811-404: 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

11938-551: The margins of the Mediterranean and Black Sea basins. Cfa zones are generally transitional between the Mediterranean climate zones along the coast and oceanic and humid continental zones to the west and north where rainfall in the warmer months is too high for a Mediterranean classification, while temperatures (either in the summer and/or winter) are too warm to qualify as oceanic or humid continental. Summer humidity

12065-486: The monsoon variant ( Cwa ), where rainfall peaks at the monsoon season. Closely resembling the climate patterns of neighboring Northern Indian plains , this region shows a distinct three season pattern- relatively dry and very hot summer (March- early June), extremely wet, cooler Monsoon season (June- September), and mild, foggy winter (Late October- February). Humid subtropical climates can also be found in Nepal . However,

12192-457: The months of December, January, and February. Unlike a good portion of East Asian locations with this climate however, most of Southeast Asia seldom experiences snowfall. These areas tend to feature hot and humid summers and cool and wet winters , with mean temperatures varying between 25 and 30 °C (77 and 86 °F) in summer. Although humid subtropical climates in Asia are mostly confined to

12319-590: The north-east of Spain ( Huesca ), West Macedonia in Greece ( Kozani ). Along the Black Sea coast of Bulgaria ( Varna ), coast of Romania ( Constanța and Mamaia ), Sochi, Russia and Crimea , have summers too warm (>22 °C (72 °F) mean temperature in the warmest month) to qualify as oceanic, no freezing month, and enough summer precipitation and sometimes humid conditions, where they would be fit to be classed under Cfa , though they closely border

12446-662: The northern boundary. The influence of the strong Siberian anticyclone in East Asia brings colder winter temperatures than in the humid subtropical zones in South America, and Australia. The 0 °C (32 °F) isotherm reaches as far south as the valleys of the Yellow and Wei rivers, roughly latitude 34° N . At Hainan Island and in Taiwan, the climate transitions from subtropical into tropical. In most of this region,

12573-726: The northern limit of the humid subtropical zone. The coastal areas in the northern half of the Adriatic Sea also fall within this climate zone. The cities include Trieste , Venice , and Rimini in Italy , Rijeka and Split in Croatia , Koper in Slovenia and Kotor in Montenegro . Other Southern European areas in the Cfa zone include the central valleys and coast of Catalonia of Girona and Barcelona in Spain , some on

12700-887: The northern regions. However, the humid subtropical climates exhibited here typically differ markedly from those in East Asia (and, for that matter, a good portion of the globe). Winters are typically cool to mild (sometimes reaching 0 °C (32 °F)), ranging from humid and foggy in December to dry in February. These winters are followed by a mild spring (March-April). Summers tend to be relatively longer and very hot, starting from mid-April and peaking in June, extending up to July with high temperatures often exceeding 40 °C (104 °F). Summers usually begin dry, complete with dust storms , traits typically associated with arid or semi-arid climates , before eventually transforming into

12827-453: 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

12954-522: 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

13081-466: 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

13208-440: 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

13335-413: 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

13462-444: 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

13589-492: 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

13716-492: 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

13843-513: 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

13970-457: The semi-arid and/or Mediterranean climates. Furthermore, the inland Cfa climates generally have drier summers, or at least summers with low humidity. Extreme heat is more often experienced in Sydney than in other large cities in Australia's Cfa zone, especially in the western suburbs , where highs over 40 °C (104 °F) are not uncommon. Frost is prevalent in the more inland areas of Sydney, such as Richmond . Average annual rainfall in

14097-547: The southeastern quarter of the continent, there are two narrow areas along the coast of the Caspian Sea and Black Sea with humid subtropical climates. Summers in these locations are cooler than typical humid subtropical climates and snowfall in winter is relatively common, but is usually of a short duration. In Western Asia , the climate is prevalent in the Gilan , Māzandarān and Golestan Provinces of Iran , in parts of

14224-628: The southern part of the continent. The Cwa climate is found over a large portion of the interior of the Middle and Eastern African regions. This area includes central Angola , northeastern Zimbabwe , the Niassa , Manica and Tete provinces of Mozambique , the southern Congo provinces, southwest Tanzania , and the majority of Malawi , and Zambia . Some lower portions of the Ethiopian Highlands also have this climate. The climate

14351-483: The southernmost limits, such as Tampa and Orlando and along the Texas coast around Corpus Christi down toward Brownsville generally feature warm weather year-round and minimal temperature differences between seasons. In contrast, cities at the northernmost limits of the climate zone such as New York, Philadelphia and Louisville feature hot, humid summers and chilly winters. These areas have average winter temperatures at

14478-617: 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

14605-419: 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

14732-483: 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

14859-648: 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

14986-423: 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

15113-471: The warmest month 22 °C (72 °F) or higher. However, while some climatologists have opted to describe this climate type as a "humid subtropical climate", Köppen himself never used this term. The humid subtropical climate classification was officially created under the Trewartha climate classification . In this classification, climates are termed humid subtropical when they have at least 8 months with

15240-451: 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

15367-640: The wettest month – such as in Jacksonville , Charleston , Mobile , New Orleans, and Virginia Beach. A semblance of a monsoon pattern (dry winters/wet summers) is evident along the Atlantic coast from the Chesapeake Bay region and the Outer Banks south to Florida. The seasonal monsoon is much stronger on the Florida peninsula, as most locations in Florida have dry winters and wet summers. In addition, areas in Texas that are slightly inland from

15494-402: 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

15621-537: The winter monsoon is very well developed, as such eastern Asian humid subtropical zones have a strong winter dry season and heavy summer rainfall. Only in inland areas below the Yangtze River and coastal areas between approximately the Huai River and the beginning of the coast of Guangdong is there sufficient winter rainfall to produce a Cfa climate; even in these areas, rainfall and streamflow display

15748-627: The world. Urban examples include Bratislava , Budapest , and the Innere Stadt of Vienna . In the Azores , some islands have this climate, with very mild and rainy winters (>13 °C (55 °F)) and no snowfall, warm summers (>21 °C (70 °F)) but with no dry season during the warmest period, which means that they can neither be classified as oceanic , nor as Mediterranean , only as humid subtropical, as with Corvo Island . In many other climate classification systems outside of

15875-795: 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

16002-527: 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

16129-585: 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

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