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Typhoon Ophelia was a long-lived and powerful tropical cyclone that had devastating impacts on the small atoll of Ulithi in the Caroline Islands. Forming as a tropical depression on November 21, 1960 near Enewetak Atoll, the incipient cyclone struggled to develop. Moving haphazardly along an s-shaped track over the western Pacific Ocean, it degenerated into a disturbance two days later. By November 27, the system reorganized and was classified a tropical depression for a second time well to the southeast of Guam. Moving slowly west-southwest, it steadily intensified into a tropical storm later that day and further into a typhoon on November 29 as it gained a steady westward track. The following day, the eye of Ophelia passed directly over Ulithi atoll with winds estimated at 230 km/h (145 mph). Turning gradually to the north, the typhoon attained peak winds of 250 km/h (155 mph) on December 1. Maintaining strength as a powerful system for several days, the storm remained over open waters. By December 4, it began to weaken as upper-level winds became unfavorable and forced the cyclone to move northeast. Passing Japan well to the southeast that day, its large circulation brought increased winds to the Tokyo area and heavy rain and snow to parts of the nation. Ophelia soon underwent an extratropical transition as it raced over the open Pacific, completing this structural change by December 6. Its remnants later crossed the International Dateline and dissipated over the Gulf of Alaska on December 10. Ophelia devastated much of Ulithi during its passage, damaging or destroying most structures and killing two people. Agriculture across the area was decimated and geographic changes to coastlines were noted. In Ophelia's wake, dramatic societal changes in the Ulithian culture arose. Traditional values were abandoned in favor of more western ones, with younger individuals attaining a notable increase in power. The local King was disposed of shortly after the storm and a total change in authority took place. In addition to the severe impact in Ulithi, the typhoon was blamed for the deaths of five fishermen when their vessel collided with a coral reef. The name ''Ophelia'' was later retired, though unusually its removal was due to its meteorological significance due to its long track and prolonged time as a significant typhoon rather than for loss of life or damage. ==Meteorologist history== On November 21, 1960, the formation of a small low-pressure area was noted following a shift in surface winds on Kwajalein Atoll in the Marshall Islands. Slowly developing, the low organized into a tropical depression by 1200 UTC, the 24th of the season. At this time, it was situated 270 km (165 mi) southwest of Enewetak Atoll. Though classified a depression, maximum sustained winds were only estimated at 35 km/h (25 mph). For unknown reasons, the system soon became diffuse and abruptly shifted direction to the east-southeast. Concurrently the cyclone lost its identity as a tropical cyclone and the Joint Typhoon Warning Center (JTWC) discontinued advisories on it by 0600 UTC on November 24. The remnant disturbance subsequently doubled back to the west, bypassing the islands of Pohnpei and Chuuk before re-intensifying.〔 A circulation began redeveloping on November 26 and at 0000 UTC the next day, the JTWC reclassified the system as a tropical depression; the rejuvenated depression was situated 465 km (290 mi) southeast of Guam at this time. Over the next two days, the storm drifted west-southwest at an average speed of 3 km/h (2 mph). Roughly 18 hours after regeneration, the depression attained tropical storm status and was assigned the name ''Ophelia''. Initially, Ophelia was forecast to turn northward and impact the Mariana Islands but it ultimately followed a "sinusoidal pattern" path west.〔 Steady intensification took place through November 30, with Ophelia attaining typhoon status at 0000 UTC on November 29. By 0800 UTC on November 29, a 24 km (15 mi) wide eye formed over the storm's center and its central pressure had fallen to 982 mbar (hPa; 29.00 inHg), as measured by a United States Navy weather reconnaissance aircraft. Within 24 hours of this it attained winds in excess of 185 km/h (115 mph), ranking it as a Category 3-equivalent typhoon on the modern-day Saffir–Simpson hurricane wind scale.〔 During the intensification process, its forward speed greatly increased to 32 km/h (20 mph). At 0300 UTC on November 30, the eye of Ophelia passed directly over the small atoll of Ulithi in the Caroline Islands; Ulithi Atoll was the only island or land mass over which the eye of the storm passed while warnings were being issued. Sustained winds there reached 230 km/h (145 mph) while a barometer measured a minimum atmospheric pressure of 939.4 mbar (hPa; 27.744 inHg). Thereafter, Ophelia acquired a more northerly component to its track.〔 The typhoon attained winds of 250 km/h (155 mph) while situated roughly halfway between the Philippines and the Mariana Islands at 0600 UTC on December 1.〔〔 Later that day the storm had turned due north and weakened slightly.〔 Maintaining an intensity between 220 and 230 km/h (140 and 145 mph), Ophelia traveled north toward Japan for two days.〔 around 0600 UTC on December 2, reconnaissance measured a pressure of 928 mb (hPa; 27.41 inHg) within the now 40 km (25 mi) wide eye of Ophelia.〔 The Japan Meteorological Agency estimated the pressure to have been slightly lower, reporting a minimum of 925 mb (hPa; 27.32 inHg). Additionally, the China Meteorological Administration assessed Ophelia to have been a stronger system, with winds of 270 km/h (165 mph). On December 4, strong upper-level westerlies forced the typhoon northeast and prompted dramatic acceleration. The typhoon's eye soon dissolved as the cyclone's structure waned. Moving at an exceptionally fast 98 km/h (61 mph), with a maximum forward speed of 120 km/h (75 mph), Ophelia began transitioning into an extratropical cyclone on December 5 and completed the transformation the following day as winds dropped below typhoon-force.〔 The briskly moving system crossed the International Dateline later on December 6 along an easterly track before turning north on December 8 south of Alaska.〔 The system subsequently dissipated over the Gulf of Alaska on December 10. Throughout its tropical phase, Ophelia tracked along a path roughly 8,050 km (5,000 mi) long.〔 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 Ophelia」の詳細全文を読む スポンサード リンク
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