[15], In general, westerly wind increases associated with the Madden–Julian oscillation lead to increased tropical cyclogenesis in all tropical cyclone basins. The typhoon is the name given specifically to the tropical cyclone that occurs in the northwest area of the Pacific Ocean and the western direction of the International Date Line. The central part of the cyclone is called as the eye. The term typhoon is the regional name in the northwest Pacific for a severe (or mature) tropical cyclone,[3] whereas hurricane is the regional term in the northeast Pacific and northern Atlantic. By Oishimaya Sen Nag on April 25 2017 in Environment. One of the strongest and deadliest tropical cyclones of the 21st Century has been Typhoon Haiyan, which devastated large areas in Southeast Asia, especially the Philippines, as recently as November 8th, 2013, killing nearly 6,300 people in the Philippines alone. When a typhoon causes damage in a country, the affected country can request for retiring the name in the next session of the ESCAP/WMO Typhoon Committee. The name cyclone is retained when referring to tropical cyclones that occur over the Southwestern Pacific and Indian Ocean. Though a reduction of the rate of global warming would be the only permanent solution to an increase in future threats from typhoons, it is also important for the governments of typhoon-prone countries to quickly devise new policies and disaster management plans to better handle the effects of these tropical cyclones in the coming years. Typhoon Violet of 1961, Typhoon Sally of 1964, Typhoon Cora of 1966, and Typhoon Bopha of 2012 are others listing among the strongest typhoons on recent record. This region is referred to as the Northwestern Pacific Basin, and is the most active tropical cyclone basin on Earth, accounting for almost one-third of the world's annual tropical cyclones. Though these storms are quite frequent in occurrence, some are more dangerous than the others. [14] Typically with Pacific typhoons, there are two outflow jets: one to the north ahead of an upper trough in the Westerlies, and a second towards the equator. Hurricanes, typhoons, and tropical cyclones all essentially refer to the same natural phenomena. Taiwan has received the wettest known typhoon on record for the northwest Pacific tropical cyclone basins. [38] The most intense storm based on minimum pressure was Typhoon Tip in the northwestern Pacific Ocean in 1979, which reached a minimum pressure of 870 hectopascals (26 inHg) and maximum sustained wind speeds of 165 knots (85 m/s, 190 mph, 310 km/h). [13], There are six main requirements for tropical cyclogenesis: sufficiently warm sea surface temperatures, atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriolis force to develop a low pressure center, a pre-existing low level focus or disturbance, and low vertical wind shear. A rare few storms, like Hurricane John, were redesignated as typhoons as they originated in the Eastern/Central Pacific and moved into the western Pacific. [10] Once the system's maximum sustained winds reach wind speeds of 64 knots (74 mph; 119 km/h), the JMA will designate the tropical cyclone as a typhoon—the highest category on its scale. While the majority of storms form between June and November, a few storms do occur between December and May (although tropical cyclone formation is at a minimum during that time). The highest reliably-estimated maximum sustained winds on record for a typhoon was that of Typhoon Haiyan at 314 km/h (195 mph) shortly before its landfall in the central Philippines on November 8, 2013. The main reason for this appears to be the phase of the Madden–Julian oscillation, or MJO, which is normally in opposite modes between the two basins at any given time.[18]. [...] The Chinese applied the [Greek] concept to a rather different wind [...]", CS1 maint: multiple names: authors list (. The area just northeast of the Philippines is the most active place on Earth for tropical cyclones to exist. From point of origin, the storm follows a northerly direction, only affecting small islands. Whether it be a depression in the Intertropical Convergence Zone (ITCZ) or monsoon trough, a broad surface front, or an outflow boundary, a low level feature with sufficient vorticity and convergence is required to begin tropical cyclogenesis. [7][9], A tropical depression is the lowest category that the Japan Meteorological Agency uses and is the term used for a tropical system that has wind speeds not exceeding 33 knots (38 mph; 61 km/h).