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Typhoon Hal (1985)
Typhoon Hal, known in the Philippines as Typhoon Kuring, was the strongest cyclone to affect southern China since 1983. Hal originated from a monsoon trough that formed in early June 1985. The system gradually became better organized, and on June 20, the storm attained tropical storm. Intensification continued and the storm reached typhoon intensity later that day. On the evening of June 21, Hal reached peak intensity, before passing south of Taiwan. The storm weakened slightly on June 22, and lost typhoon intensity two days later. Later on June 24, Hal moved onshore northeast of Hong Kong. Hal dissipated three days later. Across the Philippines, 46 people were killed, 10 of which perished due to drownings. Roughly 80% of one Pangasinan municipality was flooded. Widespread power outages were reported, and two radio towers were brought down. A total of 127,440 persons were directly affected by the typhoon. In all, about 13,000 families, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philippines
The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a total area of roughly 300,000 square kilometers, which are broadly categorized in Island groups of the Philippines, three main geographical divisions from north to south: Luzon, Visayas, and Mindanao. With a population of over 110 million, it is the world's List of countries and dependencies by population, twelfth-most-populous country. The Philippines is bounded by the South China Sea to the west, the Philippine Sea to the east, and the Celebes Sea to the south. It shares maritime borders with Taiwan to the north, Japan to the northeast, Palau to the east and southeast, Indonesia to the south, Malaysia to the southwest, Vietnam to the west, and China to the northwest. It has Ethnic groups in the Philippines, diverse ethnicities and Culture o ... [...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 primarily for the protection of U.S. 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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Cyclone Warnings And Watches
Tropical cyclone warnings and watches are alerts issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate preparation for the cyclone, including evacuation of vulnerable areas where necessary. It is important that interests throughout the area of an alert make preparations to protect life and property, and do not disregard it on the strength of the detailed forecast track. Western hemisphere New tropical cyclone position and forecast information is available at least every twelve hours in the Southern Hemisphere and at least every six hours in the Northern Hemisphere from Regional Specialized Meteorological Centers and Tropical Cyclone Warning Centers. In conjunction with the National Hurricane Center, the national meteorological and hydrological services of Central America, the northern Atla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barometric Pressure
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013.25 millibars, 760 mm Hg, 29.9212 inchesHg, or 14.696 psi.International Civil Aviation Organization. ''Manual of the ICAO Standard Atmosphere'', Doc 7488-CD, Third Edition, 1993. . The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm. In most circumstances, atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. As elevation increases, there is less overlying atmospheric mass, so atmospheric pressure decreases with increasing elevation. Because the atmosphere is thin relative to the Earth's radius—especially the dense atmospheric layer at low altitudes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luzon
Luzon ( , ) is the largest and most populous List of islands in the Philippines, island in the Philippines. Located in the northern portion of the List of islands of the Philippines, Philippine archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as well as Quezon City, the country's most populous city. With a population of 64 million , it contains 52.5% of the country's total population and is the List of islands by population, 4th most populous island in the world. It is the List of islands by area, 15th largest island in the world by land area. ''Luzon'' may also refer to one of the three primary Island groups of the Philippines, island groups in the country. In this usage, it includes the Luzon Mainland, the Batanes and Babuyan Islands, Babuyan groups of islands to the north, Polillo Islands to the east, and the outlying islands of Catanduanes, Marinduque and Mindoro, among others, to the south. The islands o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Cyclone Forecast Model
A tropical cyclone forecast model is a computer program that uses meteorology, meteorological data to weather forecasting, forecast aspects of the future state of tropical cyclones. There are three types of models: statistical, dynamical, or combined statistical-dynamic. Dynamical models utilize powerful supercomputers with sophisticated mathematical modeling software and meteorological data to numerical weather prediction, calculate future weather conditions. Statistical models forecast the evolution of a tropical cyclone in a simpler manner, by extrapolating from historical datasets, and thus can be run quickly on platforms such as personal computers. Statistical-dynamical models use aspects of both types of forecasting. Four primary types of forecasts exist for tropical cyclones: tropical cyclone track forecasting, track, intensity, storm surge, and tropical cyclone rainfall climatology, rainfall. Dynamical models were not developed until the 1970s and the 1980s, with e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Cyclone Naming
Tropical cyclones and subtropical cyclones are named by various warning centers to simplify communication between forecasters and the general public regarding forecasts, watches and warnings. The names are intended to reduce confusion in the event of concurrent storms in the same Tropical cyclone basins, basin. Once storms develop sustained wind speeds of more than , names are generally assigned to them from predetermined lists, depending on the basin in which they originate. Some tropical depressions are named in the Western Pacific, while tropical cyclones must contain a significant amount of gale-force winds before they are named in the Southern Hemisphere. Before it became standard practice to give Given name, personal (first) names to tropical cyclones, they were named after places, objects, or the saints' feast days on which they occurred. Credit for the first usage of personal names for weather systems is generally given to Queensland Government meteorologist Clement Wr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philippine Atmospheric, Geophysical And Astronomical Services Administration
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (, abbreviated as PAGASA , which means "hope" as in the Tagalog word ''pag-asa'') is the National Meteorological and Hydrological Services (NMHS) agency of the Philippines mandated to provide protection against natural calamities and to ensure the safety, well-being and economic security of all the people, and for the promotion of national progress by undertaking scientific and technological services in meteorology, hydrology, climatology, astronomy and other geophysical sciences. Created on December 8, 1972, by reorganizing the Weather Bureau, PAGASA now serves as one of the Scientific and Technological Services Institutes of the Department of Science and Technology. History The ''Observatorio Meteorológico de Manila'' Formal meteorological and astronomical services in the Philippines began in 1865 with the establishment of the ''Observatorio Meteorológico de Manila'' (Manila Meteorologica ... [...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 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 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-minute period. In the W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maximum Sustained Winds
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 certain distance from the center, known 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 mean sea level, 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 is often used to estimate the maximum sustained winds within a tropical cyclone. Land, ship, aircraft reconnaissance observations, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Convection
Atmospheric convection is the vertical transport of heat and moisture in the atmosphere. It occurs when warmer, less dense air rises, while cooler, denser air sinks. This process is driven by parcel-environment instability, meaning that a "parcel" of air is warmer and less dense than the surrounding environment at the same altitude. This difference in temperature and density (and sometimes humidity) causes the parcel to rise, a process known as buoyancy. This rising air, along with the compensating sinking air, leads to mixing, which in turn expands the height of the planetary boundary layer (PBL), the lowest part of the atmosphere directly influenced by the Earth's surface. This expansion contributes to increased winds, cumulus cloud development, and decreased surface dew points (the temperature below which condensation occurs). Convection plays a crucial role in weather patterns, influencing cloud formation, wind, and the development of thunderstorms, which can be associa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Shear
Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal wind shear. Vertical wind shear is a change in wind speed or direction with a change in altitude. Horizontal wind shear is a change in wind speed with a change in lateral position for a given altitude. Wind shear is a microscale meteorological phenomenon occurring over a very small distance, but it can be associated with mesoscale or synoptic scale weather features such as squall lines and cold fronts. It is commonly observed near microbursts and downbursts caused by thunderstorms, fronts, areas of locally higher low-level winds referred to as low-level jets, near mountains, radiation inversions that occur due to clear skies and calm winds, buildings, wind turbines, and sailboats. Wind shear has significant effects on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
