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Cyclone Fay was an intense, late-season tropical cyclone which struck Western Australia during the 2003-04 Australian region cyclone season. Forming from an area of low pressure on 12 March, Fay was the only Category 5 cyclone during the season. The system had a minimum pressure of 910 mbar (hPa; 26.87 inHg) and maximum sustained winds of .〔(【引用サイトリンク】url=http://www.bom.gov.au/cyclone/history/pdf/fay.pdf )〕 Moving towards the southwest and eventually towards the south, Fay gradually strengthened as it paralleled the northwestern coast of Australia, and made landfall on the Pilbara coast on the morning of 27 March as a Category 4 cyclone. While no fatalities were reported, the cyclone brought record-breaking rainfall to Australia, which led to a sharp decrease in the country's gold output. The cyclone also caused minor damage in the Pilbara region of Western Australia. In the spring of 2005, the Australian Bureau of Meteorology retired the name ''Fay'' from use, and it will never be used again as a cyclone name. ==Meteorological history== The low pressure system that later developed into Fay formed in the Gulf of Carpentaria on 12 March 2004.〔 Through 15 March satellite imagery indicated increasing convection and organisation of the system, as well as decreasing wind sheer aloft, adding to the favourable conditions for strengthening. On 16 March, the system was designated Tropical Cyclone 18S by the Joint Typhoon Warning Center, with winds of .〔(【引用サイトリンク】url=http://www.australiasevereweather.com/cyclones/2004/fay.htm )〕 The system then crossed Melville and Bathurst Islands and moved into the Timor Sea, where it intensified, and was given the name Fay by the Australian Bureau of Meteorology.〔 Fay began to turn southward on 17 March; simultaneously, the cyclone continued to intensify due to a weakening of vertical wind shear, and well-defined outflow became apparent on satellite imagery. The following day, a steering ridge to the south of the system strengthened and pushed the cyclone away from the coast and to the northwest.〔 At the same time, the system continued to intensify due to the favourable environment in the upper atmosphere. However, hot, dry air flowing into the system from the south, combined with vertical wind sheer, kept the storm from strengthening as much at its maximum potential rate.〔 By 19 March Fay's track had turned to the west-southwest,〔 and over the next day it continued to strengthen in due to favourable upper level outflow and weak vertical sheer.〔 On 21 March, Fay became a Category 5 cyclone on the Australian Region Tropical Cyclone Intensity Scale.〔 A mid-latitude trough caused the steering ridge to weaken, and subsequently, Fay to turn to the south.〔 Over the next two days, the environmental shear around the cyclone decreased, which would normally have led to intensification; however, as the shear decreased, the cyclone also moved over an area of dry air, weakening the system. By 23 March, Fay had moved in a loop, and the system weakened to a Category 2.〔 Over the next day, favourable outflow counteracted the dry air that had weakened the system, and a banding eye feature was observed on satellite imagery.〔 Fay then encountered moister air as it moved southward, leading it to re-intensify on 25 March.〔 A weak eye of 10 nm was observed on 26 March which grew to 15 nm as the day went on.〔 Strengthening into a Category 4 system early on 27 March, Fay made landfall on the Pilbara coast between 8 am and 9 am AWST (0000 and 0100 UTC) with winds of , weakening below cyclone strength somewhere between the towns of Nullagine and Telfer.〔 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「Cyclone Fay」の詳細全文を読む スポンサード リンク
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