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Hurricane Genevieve, also referred to as Typhoon Genevieve, was the fourth-most intense tropical cyclone of the North Pacific Ocean in 2014. A long-lasting system, Genevieve was the first one to track across all three northern Pacific basins since Hurricane Jimena in 2003. Genevieve developed from a tropical wave into the eighth tropical storm of the 2014 Pacific hurricane season well east-southeast of Hawaii on July 25. However, increased vertical wind shear caused it to weaken into a tropical depression by the following day and degenerate into a remnant low on July 28. Late on July 29, the system regenerated into a tropical depression, but it weakened into a remnant low again on July 31, owing to vertical wind shear and dry air. The remnants redeveloped into a tropical depression and briefly became a tropical storm south of Hawaii on August 2, yet it weakened back into a tropical depression soon afterwards. Late on August 5, Genevieve re-intensified into a tropical storm, and intensified into a category 1 hurricane on the next day when undergoing rapid deepening because of favorable conditions. Early on August 7, Genevieve strengthened into a category 4 hurricane, shortly before it crossed the International Date Line and was reclassified as a typhoon, also becoming the thirteenth named storm of the 2014 Pacific typhoon season. Late on the same day, Genevieve reached peak intensity, when it was located west-southwest of Wake Island. Typhoon Genevieve started to gradually weaken at noon on August 8, because stronger vertical wind shear provided by a TUTT cell began to weaken the system further on August 9. The typhoon crossed 30° north at noon on August 10 and weakened to a severe tropical storm soon afterwards, because of unfavorable sea surface temperature and expanding subsidence. Genevieve weakened into a tropical storm on August 11 and a tropical depression the following day, as its deep convection diminished. ==Origin and regeneration== The National Hurricane Center (NHC) began to monitor a tropical wave associated with a few showers and thunderstorms, moving westward off the coast of northern Central America on July 17. Four days later, thunderstorm activity became more concentrated; by July 22, the area of low-pressure became better organized. On July 23, the NHC noted that the system could become a tropical depression within the next two days; however, they also noted that wind shear could increase within a couple of days. Following an increase of deep convection developing near the center as well as the collection of ASCAT data showing an area of tropical storm-force winds, the NHC upgraded the system to Tropical Storm Genevieve on July 25. Shortly thereafter, the system attained its initial peak intensity of 45 mph (75 km/h). Shortly afterward, increased wind shear took its toll on the system, causing Genevieve to lose its organization as it continued westward, under the influence of a subtropical ridge and the Intertropical Convergence Zone. After the low-level center of circulation was exposed and became separated from the deep convection, the NHC subsequently downgraded it to a tropical depression on July 26. Although deep convection increased near the center early the next day, Genevieve continued to battle westerly shear when crossing 140°W, moving into the waters monitored by the Central Pacific Hurricane Center (CPHC). Due to the lack of deep convection, the CPHC indicated that Genevieve had become a post-tropical remnant low early on July 28, as only a low-level cloud swirl remained. However, the CPHC noted the possibility of re-development since shear was forecast to decrease. Roughly 36 hours later, the remnants of Genevieve regenerated into a tropical depression to the southeast of the main Hawaiian Islands. The system briefly became better organized on July 30, and thus the CPHC forecast the storm re-intensify into a tropical storm. But by early the next day, the low-level circulation center became displaced to east of deep convection, due to increased shear and dry air. By 21:00 UTC July 31, the CPHC reported that Genevieve had once again degenerated to a remnant low as only isolated area of deep convection remained. 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 Genevieve (2014)」の詳細全文を読む スポンサード リンク
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