Cyclone Evan
Severe Tropical Cyclone Evan was considered to be the worst tropical cyclone to affect the island nation of Samoa since Cyclone Val in 1991 and was formerly the strongest storm to impact the main islands until Winston in 2016. The system was first noted on December 9, 2012, as a weak tropical depression about to the northeast of Suva, Fiji. Over the next couple of days the depression gradually developed further before it was named Evan on December 12, as it had developed into a tropical cyclone. During that day the system moved toward the Samoan Islands and gradually intensified, before the system slowed and severely affected the Samoan Islands during the next day with wind gusts of up to . The storm moved east and impacted the French islands of Wallis and Futuna before affecting Samoa and American Samoa. On December 16 Evan turned to the south and paralleled western areas of Fiji. Meteorological history During December 9, the Fiji Meteorological Service started to monitor ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Samoa
Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands (Savai'i and Upolu); two smaller, inhabited islands (Manono Island, Manono and Apolima); and several smaller, uninhabited islands, including the Aleipata Islands (Nu'utele, Nu'ulua, Fanuatapu and Namua). Samoa is located west of American Samoa, northeast of Tonga (closest foreign country), northeast of Fiji, east of Wallis and Futuna, southeast of Tuvalu, south of Tokelau, southwest of Hawaii, and northwest of Niue. The capital city is Apia. The Lapita culture, Lapita people discovered and settled the Samoan Islands around 3,500 years ago. They developed a Samoan language and Samoan culture, Samoan cultural identity. Samoa is a Unitary state, unitary Parliamentary system, parliamentary democracy with 11 Administrative divisions of Samoa, administrative divisions. It is a sovereign state and a member of the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Squall
A squall is a sudden, sharp increase in wind speed lasting minutes, as opposed to a wind gust, which lasts for only seconds. They are usually associated with active weather, such as rain showers, thunderstorms, or heavy snow. Squalls refer to the increase of the sustained winds over that time interval, as there may be higher gusts during a squall event. They usually occur in a region of strong sinking air or cooling in the mid-atmosphere. These force strong localized upward motions at the leading edge of the region of cooling, which then enhances local downward motions just in its wake. Etymology There are different versions of the word's origins: * By one version, the word appears to be Nordic in origin, but its etymology is considered obscure. It probably has its roots in the word ''skvala'' an Old Norse word meaning literally ''to squeal''. * By another version, it is an alteration of ''squeal'' influenced by ''bawl''. Character of the wind The term "squall" is used to refe ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Low Pressure
In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible rain or storms), while high-pressure areas are associated with lighter winds and clear skies. Winds circle anti-clockwise around lows in the northern hemisphere, and clockwise in the southern hemisphere, due to opposing Coriolis forces. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the atmosphere (aloft). The formation process of a low-pressure area is known as cyclogenesis. In meteorology, atmospheric divergence aloft occurs in two kinds of places: * The first is in the area on the east side of upper troughs, which form half of a Rossby wave within the Westerlies (a trough with large wavelength that extends through the troposphere). * A second is an area where wind divergence aloft occurs a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure without a closed isobaric contour that would define it as a low pressure area. Since low pressure implies a low height on a pressure surface, troughs and ridges refer to features in an identical sense as those on a topographic map. Troughs may be at the surface, or aloft. Near-surface troughs sometimes mark a weather front associated with clouds, showers, and a wind direction shift. Upper-level troughs in the jet stream (as shown in diagram) reflect cyclonic filaments of vorticity. Their motion induces upper-level wind divergence, lifting and cooling the air ahead (downstream) of the trough and helping to produce cloudy and rain conditions there. Unlike fronts, there is not a universal symbol for a trough on a surface weather analysis chart. The weather charts in some countries or regions mark troughs by a line. In the United States, a trough may be marked as a dashed line or bold line. In the UK, Hong Kong ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cyclone Evan, Fiji (10690392825)
In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an anticyclone). Cyclones are characterized by inward-spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale (the synoptic scale). Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes, and dust devils lie within smaller mesoscale. Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of the tropical upper tropospheric trough during the summer months in the Northern Hemisphere. Cyclones have also been seen on extraterrestrial planets, such as Mars, Jupiter, and Neptune. Cyclogenesis is the process of cyclone formation and ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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World Meteorological Organization
The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics. The WMO originated from the International Meteorological Organization, a nongovernmental organization founded in 1873 as a forum for exchanging weather data and research. Proposals to reform the status and structure of the IMO culminated in the World Meteorological Convention of 1947, which formally established the World Meteorological Organization. The Convention entered into force on 23 March 1950, and the following year the WMO began operations as an intergovernmental organization within the UN system. The WMO is made up of 193 countries and territories, and facilitates the "free and unrestricted" exchange of data, information, and research between the respective meteorological and hydrological institutions of its members. It also collaborates with nongovernmental partners ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Meteorological Service Of New Zealand Limited
Meteorological Service of New Zealand Limited (MetService - Te Ratonga Tirorangi) is the national meteorological service of New Zealand. MetService was established as a state-owned enterprise in 1992. It employs about 300 staff, and its headquarters are in Wellington, New Zealand. Prior to becoming an SOE, New Zealand's national meteorological service has existed in a number of forms since the appointment of the country's first Director of Meteorological Stations in August 1861. As New Zealand's national meteorological service, MetService produces and issues forecasts and official weather warnings on behalf of New Zealand's Ministry of Transport and is certified by the Civil Aviation Authority of New Zealand. International media, aviation and energy business is conducted under the ''MetraWeather'' brand. MetService has been certified to the ISO 9001 standard since November 1995. History The weather forecasting service began in 1861, when a spate of shipwrecks prompted the Gov ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Viti Levu
Viti Levu (pronounced ) is the largest island in the Republic of Fiji. It is the site of the nation's capital, Suva, and home to a large majority of Fiji's population. Geology Fiji lies in a tectonically complex area between the Australian Plate and the Pacific Plate. The Fiji Platform lies in a zone bordered by active extension fault lines, around which most of the shallow earthquakes in the area have been centred. These fault lines are: the Fiji Fracture Zone (FFZ) to the north; the 176° Extension Zone (176°E EZ) to the west; and the Hunter Fracture Zone (HFZ) and Lau Ridge to the east. The oldest rocks on the island are those formed during the Eocene and Lower Miocene epochs that belong to the Wainimala group. The lower portion of the group is made up of volcanic flows and volcanoclastics, which grade from basalt to trachyte and rhyolite. Geographically, this group is found south of Nadi, including on the peaks of Koromba (at 3528 feet high) and Natambumgguto (at 1242 ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Australian Tropical Cyclone Intensity Scale
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-minu ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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 atmospheric pr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |