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Severe Tropical Cyclone Kathy was a powerful tropical cyclone that devastated the Sir Edward Pellew Group of Islands in March 1984. Originating from a tropical low off the southern coast of Papua New Guinea. Tracking westward, the system attained gale-force winds by 18 March before striking the Cape York Peninsula. After crossing the area, Kathy entered the Gulf of Carpentaria where environmental conditions favoured significant development. On 22 March, the storm attained its peak intensity as a Category 5 severe tropical cyclone (Australian tropical cyclone intensity scale) with ten-minute sustained winds of 205 km/h (125 mph). By this time, the storm had been tracking towards the southwest and struck the Sir Edward Pellew Group of Islands later on 22 March before moving over the Australian mainland as a slightly weaker system. Once over land, Kathy rapidly degraded, losing gale-force winds within 24 hours; the storm dissipated over the Northern Territory on 24 March. Moving through the Pellew Islands as a powerful cyclone, Kathy generated a maximum storm surge of and winds exceeding . Offshore, 20 vessels were affected, one of which sank and resulted in the death of its captain. In mainland Australia, the system struck a relatively sparsely populated area, with only Borroloola being significantly impacted by the cyclone. Additionally, mangroves at along the McArthur River sustained substantial damage. Overall, losses from the storm were placed at A$12 million (A$30.5 million 2011 AUD; US$24.1 million 2011 USD). Following its usage, the name ''Kathy'' was retired and will never be used again to name an Australian cyclone. ==Meteorological history== On 16 March 1984, the Bureau of Meteorology began monitoring a tropical low off the southern coast of Papua New Guinea for possible development into a tropical cyclone. Over the following day, the system quickly developed and attained gale-force winds as it neared the Cape York Peninsula. Attaining a pressure of 990 hPa (mbar; 29.23 inHg), the weak system made landfall just north of Weipa, Queensland on 19 March before losing strength. Though already considered a tropical cyclone for two days by the Bureau, the Joint Typhoon Warning Center (JTWC) issued their first advisory on the system just prior to its landfall; however, they considered it to be a tropical depression rather than a storm. After roughly 12 hours over land, a weakened Kathy emerged over the warm waters of the Gulf of Carpentaria on 20 March.〔 Once over water, the JTWC classified the system as a tropical storm.〔 Turning southwestward, the storm entered a region favoring significant development and soon began a period of rapid intensification.〔 Intensification took place through 22 March as convection deepened around Kathy's centre and a well-defined eye formed.〔 The system reached its peak strength as a Category 5 severe tropical cyclone on the Australian tropical cyclone intensity scale with ten-minute sustained winds of 205 km/h (125 mph). Operational analysis of the storm indicated a minimum pressure of 920 hPa (mbar; 27.17 inHg);〔 however, a reassessment in 2009 concluded that Kathy's pressure had been slightly lower, bottoming out at 916 hPa (mbar; 27.05 inHg). Additionally, the JTWC assessed the system to have been slightly stronger, estimating peak one-minute sustained winds at 250 km/h (155 mph). At this time, the storm was estimated to have a Dvorak technique rating of 7.0, equivalent to a Category 5 on the Saffir–Simpson Hurricane Scale; As Cyclone Kathy neared the Australia coastline later on 22 March, it began to weaken as it interacted with land.〔 Radar imagery depicted the system as having an eye in diameter.〔 Roughly 5 hours after peaking, the storm passed directly over the Sir Edward Pellew Group of Islands, resulting in a degrading structure.〔〔 Near midnight, the system weakened to a Category 4 cyclone and made landfall in a remote region near Borroloola. Based on a wind gust to sustained ratio of 1.4, Kathy was estimated to have moved onshore with winds between 165 and 185 km/h (105 and 115 mph).〔 In the hours after landfall, Kathy rapid weakened, no longer retaining gale-force winds once away from the Gulf on 23 March. Later that day, the system turned south-westward and persisted for another 24 hours before dissipating.〔 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 Kathy」の詳細全文を読む スポンサード リンク
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