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Super Typhoon Yuri was a powerful Category 5 tropical cyclone that formed in November 1991. It was the strongest storm in 1991. The nineteenth typhoon and final super typhoon of the 1991 Pacific typhoon season, it formed as a tropical depression on November 22, about 1,590 kilometers east of Truk Island. Moving rather slowly at first, the system continued to intensify, and was given the name Yuri. It had become a severe tropical storm about 1,480 kilometers east of Truk Island and took on a west-northwestward track at 22 km/h. Typhoon intensity was attained that night when Yuri was 1,050 km east of Truk Island. Yuri turned more to the west on 26 November and reached peak intensity the following morning packing winds of over 220 km/h near its centre. Moving northwestwards at 30 km/h, Yuri passed 140 km to the south-southwest of Guam on the evening of November 27. After recurving November 29, Yuri accelerated northeastwards on 30 November and weakened to a severe tropical storm that night. By the morning of December 1, it had degenerated into a tropical storm about a few hundred kilometers east-northeast of Iwo Jima. Extratropical transition was completed soon afterwards.〔 Although Yuri never directly made landfall, it still had managed to cause $3 million (1991 USD) in damage to Pohnpei, including the loss of a radio tower. In Guam, the storm caused extensive beach erosion and destroyed between 60 and 350 buildings. There, damage totaled to $33 million (1991 USD).〔Joint Typhoon Warning Center.(“Super Typhoon Yuri” ) Retrieved on 2007-05-18.〕 It is one of the most closely observed storms ever, its eye was studied for research. ==Meteorological history== In mid-November, the presence of low-level westerlies in the central Pacific provided suitable atmospheric conditions for tropical cyclogenesis. The rapid development of thunderstorm activity near the Marshall Islands on November 16 prompted the Joint Typhoon Warning Center (JTWC) to monitor the area for signs of development. The disturbance tracked slowly in a counter-clockwise loop over the next few days as it slowly organized,〔 and at 0000 UTC on November 22, the Japan Meteorological Agency (JMA) classified the system as a tropical depression, with the JTWC following suit about a day later. Upon becoming classified as a tropical cyclone, the disturbance intensified at a fast pace, reaching tropical storm strength based on satellite intensity estimates on November 23. Yuri later reached typhoon intensity at 1200 UTC on November 24 located roughly 335 km (210 mi) east of Pohnpei while exhibiting an eye. At 0540 UTC on November 25, Yuri passed 85 km (55 mi) north of Pohnpei with winds of 140 km/h (85 mph).〔 During this time, the typhoon began a phase of unimpeded and steady intensification, contrary to most intense typhoons which typically strengthen dramatically in short bursts. Concurrently, Yuri expanded in size, reaching a maximum diameter of 600 km (370 mi) at one point.〔 At 0000 UTC on November 27, the JMA assessed the storm to have reached its peak intensity with maximum sustained winds of 220 km/h (140 mph) and a minimum barometric pressure of 895 mbar (hPa; 26.43 inHg).〔 The JTWC analyzed winds at this time to have been equivalent to a Category 5 on the Saffir–Simpson hurricane wind scale—the highest classification possible.〔 Rounding the western periphery of a subtropical ridge, Yuri began to take a more northerly course, bringing it to within 100 km (60 mi) of Guam on November 27 as a strong typhoon. After passing south of the island, the typhoon weakened but continued to grow in size, reaching an estimated 900 km (560 mi) in diameter upon clearing the Northern Mariana Islands. After recurving towards the northeast, Yuri weakened below typhoon status early on December 1 shortly before transitioning into an extratropical cyclone;〔 these remnants continued to track northward before they were last noted on December 3.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Typhoon Yuri (1991)」の詳細全文を読む スポンサード リンク
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