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Hurricane Joaquin ( ) was a powerful tropical cyclone that devastated several districts of the Bahamas and caused damage in the Turks and Caicos Islands, parts of the Greater Antilles, and Bermuda. The tenth named storm, third hurricane, and second major hurricane of the 2015 Atlantic hurricane season, Joaquin evolved from a non-tropical low to become a tropical depression on September 28, well southwest of Bermuda. Tempered by unfavorable wind shear, the depression drifted southwestward. After becoming a tropical storm the next day, Joaquin underwent rapid intensification, reaching hurricane status on September 30 and Category 3 major hurricane strength on October 1. Meandering over the southern Bahamas, Joaquin's eye passed near or over several islands. On October 3, the hurricane weakened somewhat and accelerated to the northeast. Abrupt re-intensification ensued later that day, and Joaquin acquired sustained winds of 155 mph (250 km/h); this made it the strongest Atlantic hurricane since 2010's Igor. Hurricane warnings were hoisted across most of the Bahamas as the hurricane threatened the country. Battering the nation's southern islands for over two days, Joaquin caused extensive devastation, most notably on Acklins, Crooked Island, Long Island, Rum Cay, and San Salvador Island. Severe storm surge inundated many communities, trapping hundreds of people in their homes; flooding persisted for days after the hurricane's departure. Prolonged, intense winds brought down trees and powerlines, and unroofed homes throughout the affected region. As airstrips were submerged and heavily damaged, relief workers were limited in their ability to quickly help affected residents. Joaquin was one of the strongest storms on record to affect the nation. Offshore, the American cargo ship ''El Faro'' and her 33 crew members were lost to the hurricane. Coastal flooding also impacted the nearby Turks and Caicos, washing out roadways, compromising seawalls, and damaging homes. Strong winds and heavy rainfall caused some property damage in eastern Cuba. One fisherman died when heavy seas capsized a small boat along the coast of Haiti. Storm tides resulted in severe flooding in several of Haiti's departments, forcing families from their homes and destroying crops. The weakening hurricane passed just west of Bermuda on October 4, attended by strong winds that cut power to 15,000 electric subscribers. Damage on Bermuda was minor. Although Joaquin steered clear of the mainland United States, another large storm system over the southeastern states drew tremendous moisture from the hurricane, resulting in catastrophic flooding in South Carolina. ==Meteorological history== On September 25, 2015, the US National Hurricane Center (NHC) began monitoring an upper-level low, accompanied by a surface trough, several hundred miles south-southwest of Bermuda for possible tropical cyclogenesis. The system gradually consolidated as it drifted north-northwest, acquiring a closed surface low late on September 26. Convective showers and thunderstorms steadily increased on September 27, and at 03:00 UTC on September 28 the NHC assessed the system to have become a tropical depression, situated roughly 405 mi (650 km) southwest of Bermuda. Although the depression featured a well-defined low, strong wind shear displaced convection and exposed the circulation. A ridge to the north was forecast to steer the system slowly northwest into a region of higher shear; meteorologists at the NHC initially depicted the system dissipating within 96 hours based on modeling depictions.〔 Convection developed and persisted closer to the circulation centre throughout September 28, and early on September 29 Dvorak satellite classifications indicated the system became a tropical storm. Accordingly, it was assigned the name ''Joaquin'', becoming the tenth named storm of the season. Strengthening of the mid-level ridge prompted a sudden shift in Joaquin's trajectory to the southwest, directing it towards the Bahamas.〔 Forecasters at the NHC noted considerable uncertainty in the future of Joaquin, with forecast models depicting a wide range of possibilities. Throughout September 29 the storm steadily intensified as its circulation became embedded within deep convection and upper-level outflow became increasingly prominent. High sea surface temperatures and decreasing shear aided strengthening, and early on September 30 the storm achieved hurricane status. Rapid intensification ensued thereafter, with an eye developing within a symmetric central dense overcast. Data from aircraft reconnaissance indicated that Joaquin reached Category 3 status on the Saffir–Simpson hurricane wind scale by 03:00 UTC on October 1. Around 15:00 UTC the eye of Joaquin passed over Samana Cay, Bahamas, with winds of 125 mph (205 km/h). Hours later the system further intensified to Category 4 status, attaining maximum sustained winds of 130 mph (215 km/h), as its eye contracted from in diameter. At this time Joaquin was located just 15 mi (25 km) northwest of Crooked Island. The storm's central pressure bottomed out at 931 mbar (hPa; 27.49 inHg) around 00:00 UTC on October 2. As the ridge previously steering Joaquin southwest began retreating north, the hurricane's movement slowed and shifted west, and later north, early on October 2.〔 An eyewall replacement cycle—a process whereby a second, larger eye develops while the inner eye collapses—began that morning; its eye became increasingly ill defined in satellite imagery. Slight weakening took place accordingly, and the hurricane passed over Rum Cay and San Salvador Island around 18:00 UTC and 21:00 UTC as a low-end Category 4 and high-end Category 3 respectively; a pressure near 944 mbar (hPa; 27.88 inHg) was observed on San Salvador Island. An amplifying trough over the Southeastern United States enhanced southwesterly flow over Joaquin on October 3 and prompted the hurricane to accelerate northeast away from the Bahamas. Throughout the day the storm's eye became increasingly defined and re-intensification ensued. Aircraft reconnaissance found a considerably stronger system that afternoon; based on flight-level winds of 166 mph (267 km/h), it is estimated that Joaquin attained surface winds of 155 mph (250 km/h)—a high-end Category 4 hurricane—by 16:00 UTC. Shortly after peaking, the hurricane's overall structure began to deteriorate, signalling a weakening trend. On October 4 the storm curved towards the north-northeast between a large low pressure system to its west and a mid-level ridge to its east. As deep convection over its core continued to wane, Joaquin passed about west-northwest of Bermuda near 00:00 UTC on October 5, at Category 2 intensity. The weakening trend slowed that day as the storm's satellite presentation improved slightly, marked by brief reappearances of a distinct eye feature. Joaquin gradually turned northeastward around the periphery of the weak ridge, and subsequently accelerated toward the east-northeast as it entered the prevailing westerlies. The system maintained hurricane intensity until 15:00 UTC on October 7, by which point strengthening wind shear and an increasingly colder environment began to take their toll. The cloud pattern became lopsided as colder, drier air infiltrated the circulation, forming the first stages of a frontal structure. With its extratropical transition well underway, Joaquin lost its identity as a tropical cyclone at 03:00 UTC on October 8, about southeast of Cape Race, Newfoundland. During the next several days, Joaquin's extratropical remnant continued heading eastward across the Atlantic, before reaching Portugal on October 10.〔http://www.met.fu-berlin.de/de/wetter/maps/Analyse_20151010.gif〕 During the next 5 days, Joaquin's remnant slowly moved southward along the coast of Portugal, until the system was absorbed by another frontal system to the east of Spain, on October 15.〔http://www.met.fu-berlin.de/de/wetter/maps/Analyse_20151015.gif〕 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「Hurricane Joaquin」の詳細全文を読む スポンサード リンク
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