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Cyclone Dina
Intense Tropical Cyclone Dina was a cyclone that caused record flooding across parts of Réunion. Originating from a tropical disturbance on 15 January 2002 near the Chagos Archipelago, the precursor to Dina quickly developed within a region favoring tropical cyclogenesis. By January 17, the system had developed enough organized convection as it moved southwestward to be declared a tropical depression. Rapid intensification occurred shortly thereafter, with the system attaining winds in excess of on January 18. Dina achieved its peak intensity on January 20 as an intense tropical cyclone with maximum sustained winds of . Hours after reaching hits strength, the storm bypassed Rodrigues Island about to its north. On January 21, the storm brushed Mauritius and Réunion as an intense tropical cyclone before turning southward. Once on a southward course, steady weakening ensued and the system eventually transitioned into an extratropical cyclone on January 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauritius
Mauritius ( ; french: Maurice, link=no ; mfe, label=Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Agaléga and St. Brandon. The islands of Mauritius and Rodrigues, along with nearby Réunion (a French overseas department), are part of the Mascarene Islands. The main island of Mauritius, where most of the population is concentrated, hosts the capital and largest city, Port Louis. The country spans and has an exclusive economic zone covering . Arab sailors were the first to discover the uninhabited island, around 975, and they called it ''Dina Arobi''. The earliest discovery was in 1507 by Portuguese sailors, who otherwise took little interest in the islands. The Dutch took possession in 1598, establishing a succession of short-lived settlements over a period of about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ridge (meteorology)
A ridge or barometric ridge is a term in meteorology describing an elongated area of relatively high atmospheric pressure compared to the surrounding environment, without being a closed circulation. It is associated with an area of maximum anticyclonic curvature of wind flow. The ridge originates in the center of an anticyclone and sandwiched between two low-pressure areas, and the locus of the maximum curvature is called the ''ridge line''. This phenomenon is the opposite of a trough. Description Ridges can be represented in two ways: * On surface weather maps, the pressure isobars form contours where the maximum pressure is found along the axis of the ridge. * In upper-air maps, geopotential height isohypses form similar contours where the maximum defines the ridge. Related weather Given the direction of the winds around an anticyclonic circulation and the fact that weather systems move from west to east: *ahead of an upper-ridge, the airflow that comes from the polar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Malheureux
Cap Malheureux is a village in Mauritius located in Rivière du Rempart District. The village is administered by the Cap Malheureux Village Council under the aegis of the Rivière du Rempart District Council. According to the census made by Statistics Mauritius in 2011, the population was at 5,070. History The name ''Cap Malheureux'', meaning "Unlucky Cape", was given by the French who held the island from 1715 to 1810. The island was often the bone of contention of many great explorers of the time, including the British. In 1810 the British decided to take the island in order to stop the raids on British fleets by the corsairs. Following an unsuccessful attempt to invade via Grand Port in the south in August 1810 (claimed as the only defeat in the Napoleonic Wars of the Royal Navy by the French), British navy and army forces from Bombay, Madras and the Cape of Good Hope took the French by surprise by landing in the North of the island, where the French defences were weakest. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eyewall Replacement Cycle
In meteorology, eyewall replacement cycles, also called concentric eyewall cycles, naturally occur in intense tropical cyclones, generally with winds greater than , or major hurricanes ( Category 3 or above). When tropical cyclones reach this intensity, and the eyewall contracts or is already sufficiently small, some of the outer rainbands may strengthen and organize into a ring of thunderstorms—a new, outer eyewall—that slowly moves inward and robs the original, inner eyewall of its needed moisture and angular momentum. Since the strongest winds are in a tropical cyclone's eyewall, the storm usually weakens during this phase, as the inner wall is "choked" by the outer wall. Eventually the outer eyewall replaces the inner one completely, and the storm may re-intensify. The discovery of this process was partially responsible for the end of the U.S. government's hurricane modification experiment Project Stormfury. This project set out to seed clouds outside the eyewall, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maximum Sustained Wind
The maximum sustained wind associated with a tropical cyclone is a common indicator of the intensity of the storm. Within a mature tropical cyclone, it is found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unlike gusts, the value of these winds are determined via their sampling and averaging the sampled results over a period of time. Wind measuring has been standardized globally to reflect the winds at above the Earth's surface, and the maximum sustained wind represents the highest average wind over either a one-minute (US) or ten-minute time span (see the definition, below), anywhere within the tropical cyclone. Surface winds are highly variable due to friction between the atmosphere and the Earth's surface, as well as near hills and mountains over land. Over the ocean, satellite imagery determines the value of the maximum sustained winds within a tropical cyclone. Land, ship, aircraft reconnaissance observations, and radar imagery can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Dense Overcast
The central dense overcast, or CDO, of a tropical cyclone or strong subtropical cyclone is the large central area of thunderstorms surrounding its circulation center, caused by the formation of its eyewall. It can be round, angular, oval, or irregular in shape. This feature shows up in tropical cyclones of tropical storm or hurricane strength. How far the center is embedded within the CDO, and the temperature difference between the cloud tops within the CDO and the cyclone's eye, can help determine a tropical cyclone's intensity with the Dvorak technique. Locating the center within the CDO can be a problem with strong tropical storms and minimal hurricanes as its location can be obscured by the CDO's high cloud canopy. This center location problem can be resolved through the use of microwave satellite imagery. After a cyclone strengthens to around hurricane intensity, an eye appears at the center of the CDO, defining its center of low pressure and its cyclonic wind field. Tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saffir–Simpson Scale
The Saffir–Simpson hurricane wind scale (SSHWS) classifies hurricanes—which in the Western Hemisphere are tropical cyclones that exceed the intensities of tropical depressions and tropical storms—into five categories distinguished by the intensities of their sustained winds. This measuring system was formerly known as the Saffir–Simpson hurricane scale, or SSHS. To be classified as a hurricane, a tropical cyclone must have one-minute-average maximum sustained winds at 10 m above the surface of at least 74 mph (64 kn, 119 km/h; Category 1). The highest classification in the scale, Category 5, consists of storms with sustained winds of at least 157 mph (137 kn, 252 km/h). The classifications can provide some indication of the potential damage and flooding a hurricane will cause upon landfall. The Saffir–Simpson hurricane wind scale is based on the highest wind speed averaged over a one-minute interval 10 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Cyclone Scales
Tropical cyclones are ranked on one of five tropical cyclone intensity scales, according to their maximum sustained winds and which tropical cyclone basins they are located in. Only a few scales of classifications are used officially by the meteorological agencies monitoring the tropical cyclones, but other scales also exist, such as accumulated cyclone energy, the Power Dissipation Index, the Integrated Kinetic Energy Index, and the Hurricane Severity Index. Tropical cyclones that develop in the Northern Hemisphere are unofficially classified by the warning centres on one of three intensity scales. Tropical cyclones or subtropical cyclones that exist within the North Atlantic Ocean or the North-eastern Pacific Ocean are classified as either tropical depressions or tropical storms. Should a system intensify further and become a hurricane, then it will be classified on the Saffir–Simpson hurricane wind scale, and is based on the estimated maximum sustained winds over a 1-min ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye (cyclone)
The eye is a region of mostly calm weather at the center of tropical cyclones. The eye of a storm is a roughly circular area, typically in diameter. It is surrounded by the ''eyewall'', a ring of towering thunderstorms where the most severe weather and highest winds occur. The cyclone's lowest barometric pressure occurs in the eye and can be as much as 15 percent lower than the pressure outside the storm. In strong tropical cyclones, the eye is characterized by light winds and clear skies, surrounded on all sides by a towering, symmetric eyewall. In weaker tropical cyclones, the eye is less well defined and can be covered by the central dense overcast, an area of high, thick clouds that show up brightly on satellite imagery. Weaker or disorganized storms may also feature an eyewall that does not completely encircle the eye or have an eye that features heavy rain. In all storms, however, the eye is the location of the storm's minimum barometric pressure—where the atmospheri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dvorak Technique
The Dvorak technique (developed between 1969 and 1984 by Vernon Dvorak) is a widely used system to estimate tropical cyclone intensity (which includes tropical depression, tropical storm, and hurricane/typhoon/intense tropical cyclone intensities) based solely on visible and infrared satellite images. Within the Dvorak satellite strength estimate for tropical cyclones, there are several visual patterns that a cyclone may take on which define the upper and lower bounds on its intensity. The primary patterns used are curved band pattern (T1.0-T4.5), shear pattern (T1.5–T3.5), central dense overcast (CDO) pattern (T2.5–T5.0), central cold cover (CCC) pattern, banding eye pattern (T4.0–T4.5), and eye pattern (T4.5–T8.0). Both the central dense overcast and embedded eye pattern use the size of the CDO. The CDO pattern intensities start at T2.5, equivalent to minimal tropical storm intensity (40 mph, 65 km/h). The shape of the central dense overcast is also con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Cyclone Formation Alert
A Tropical Cyclone Formation Alert (TCFA) is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Fleet Weather Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone forming from a tropical disturbance that has been monitored. Such alerts are generally always issued when it is fairly certain that a tropical cyclone will form and are not always released before cyclone genesis, particularly if the cyclone appears suddenly. The TCFA consists of several different checks that are performed by the on-duty meteorologist of the system and its surroundings. If the condition being checked is met, a certain number of points are given to the system. Parts of the TCFA Section 1 The first section of the TCFA contains information on the area of the alert as well as the estimated center of the circulation. The estimated maximum sustained winds are provided as well. Section 2 The second section generally contains more spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint Typhoon Warning Center
The Joint typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South Pacific Ocean, and Indian Ocean for all branches of the U.S. Department of Defense and other U.S. government agencies. Their warnings are intended for the protection of primarily military ships and aircraft as well as military installations jointly operated with other countries around the world. Its U.S. Navy components are aligned with the Naval Meteorology and Oceanography Command. History The origins of the Joint Typhoon Warning Center (JTWC) can be traced back to June 1945, when the Fleet Weather Center/Typhoon Tracking Center was established on the island of Guam, after multiple typhoons, including Typhoon Cobra of December 1944 and Typhoon Connie in June 1945, had caused a significant loss of men and ships. At this time the center ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
