User:林天蓬/氣旋凱文
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內文
| 二級熱帶氣旋（澳洲） | |
|---|---|
| 一級cyclone（美國） | |
 Cyclone Kelvin during its peak intensity and landfall on 18 February | |
| 形成 | 12 February 2018 |
| 消散 | 23 February 2018 |
| （20 February起退化成殘留低氣壓） | |
| 最高風速 | 10分鐘持續： 110公里/小時（70英里/小時） 1分鐘持續： 150公里/小時（90英里/小時） |
| 最低氣壓 | 974百帕（毫巴）；28.76英寸汞柱 |
| 死亡 | None |
| 損失 | $1300萬（年美元） |
| 影響地區 | Northern Territory, Western Australia, South Australia |
| 2017–18 Australian region cyclone season的一部分 | |
氣旋凱文 是2018年2月中旬影響澳大利亚西部的熱帶氣旋，2月11日該系統在北領地時被澳大利亞氣象局認定為熱帶低氣壓，之後向西南移動，2月16日從布鲁姆_(西澳大利亚)進入東印度洋，隔天增強為該風季第6個一級熱帶氣旋，隨後凱文緩慢轉向東移動，並在登陸前快速增強,並達到二級熱帶氣旋和萨菲尔-辛普森飓风等级之一級颶風的強度，凱文在登陸後的減弱速度較為緩慢，直到2月19日才減弱為熱帶低氣壓。
氣旋凱文造成金伯利地區大範圍的強降雨，造成嚴重的水患, 及財產損失, 登陸點附近基礎設施受到破壞。
氣象歷史
2月11日上午，澳大利亞氣象局將在北領地西北海岸提維群島附近的熱帶擾動升格為熱帶低氣壓，接下來數日該系統沿者澳大利亚西北部海岸向西南西移動，同時逐漸增強[1]，As the system approached the coast, the BOM began issuing warnings, and forecast the low to potentially strengthen to a category 3 severe tropical cyclone in the coming days. The Joint Typhoon Warning Center (JTWC) also issued a tropical cyclone formation alert around this time. The system emerged over the Indian Ocean at about 8:00 am AWST on 16 February, but contrary to previous forecasts was generally slow to develop.[1]
The JTWC assessed the system as having attained one-minute sustained winds of 65 km/h (40 mph) twelve hours later, and hence upgraded it to Tropical Storm 10S at 12:00 UTC.[2] The system continued to slowly strengthen, and was upgraded to a category 1 tropical cyclone by the BOM at 2:00 pm local time on the following day, and was named Kelvin.[1] Tropical Cyclone Kelvin's movement speed slowed considerably at this stage, and it proceeded to turn sharply to the east. As the system approached the coast, the period of rapid intensification that had been forecast finally eventuated.[1] This intensification, fuelled by warm sea surface temperatures and very favourable atmospheric conditions, and compounded by the small size of the system, continued until landfall.
The cyclone crossed the coast near Anna Plains Station along Eighty Mile Beach at 00:00 UTC on 18 February as a high-end category 2 tropical cyclone on the Australian scale with 10-minute sustained winds of 110 km/h (70 mph), and a central barometric pressure of 974 hPa (28.76 inHg).[1] The JTWC assessed the system as a high-end category 1 hurricane-equivalent cyclone on the Saffir-Simpson scale, with one-minute sustained winds of 150 km/h (90 mph), and a central barometric pressure of 963 hPa (28.44 inHg).[2] After making landfall, Tropical Cyclone Kelvin turned to the south-southeast, and began to track inland over the Kimberley region of Western Australia.[1] Despite losing the ocean as its primary source of energy, the cyclone was slow to weaken, partially due to the flat nature of the terrain and possibly also as a result of the brown ocean effect.[3]
The system was only downgraded below tropical cyclone intensity by the BOM after approximately 30 hours over the flat desert of Western Australia, at 2:00 pm AWST on 19 February.[1] Gale-force winds did persist in the southeastern quadrant, however, due to the influence of a high-pressure ridge to the southeast of the system. Unlike the BOM, The JTWC maintained the system's classification as a tropical storm for another 36 hours after this, only downgrading it to a tropical depression at 18:00 UTC on 20 February.[2] The remnants of the system continued to track south-southeastwards across the Great Sandy, Gibson and Great Victoria Deserts before emerging over the Great Australian Bight.[4]
影響
Tropical Cyclone Kelvin and its precursor tropical low brought widespread heavy rainfall to the regions of Western Australia across which it tracked. These parts of Australia had already experienced record rainfall totals prior to the arrival of the system, with significant amounts being delivered by Tropical Cyclone Hilda,[5] Tropical Cyclone Joyce,[6] and Tropical Low 11U.[7] Broome Airport received 376.8 mm (14.8 in) of precipitation in the 24 hours prior to 9:00 am on 17 February, while West Roebuck received 370.0 mm (14.6 in) during this time.[1] The rain delivered by Tropical Cyclone Kelvin led Broome to record a record annual rainfall total of 1506.0 mm (59.3 in) by 9:00 am on 19 February, despite being less than two months into the calendar year.[1] The heavy rainfall caused the already saturated water catchments in the region to overflow, and significant flooding ensued in areas such as Broome, Kalumburu and along the Great Northern Highway.[1]
Property damage was reported at Anna Plains Station, where the cyclone made landfall, as well as minor damage in Broome.[1] Infrastructural damage in excess of $16 million also occurred along the Great Northern Highway due to the heavy rainfall and flooding,[8][9] causing some parts of the highway to be closed and cutting off several towns in the Kimberley region for some time.[10] In addition to the heavy precipitation, Tropical Cyclone Kelvin also generated a 0.5 metre (1.6 foot) storm surge at Broome Port.[1]
References
- ^ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Tropical Cyclone Kelvin Impacts. www.bom.gov.au. [2018-02-21].
- ^ 2.0 2.1 2.2 Tropical Cyclone Kelvin Track File (JTWC).
- ^ Northern Australia's inland ocean is fuelling cyclones and creating 'landphoons'. ABC News. 2018-02-21 [2018-02-21] （澳大利亚英语）.
- ^ Analysis Chart Archive. www.bom.gov.au. [2018-02-21] （英语）.
- ^ Tropical Cyclone Hilda (报告). Australian Bureau of Meteorology. January 2018 [17 January 2018]. （原始内容存档于17 January 2018）.
- ^ Tropical Cyclone Joyce Impacts. www.bom.gov.au. [2018-02-21].
- ^ Tropical Low 11U Severe Weather Report 2018 (PDF).
- ^ Kimberley flooding leaves $16 million road repair bill after two cyclones - ABC News (Australian Broadcasting Corporation). mobile.abc.net.au. [2018-03-19] （澳大利亚英语）.
- ^ Worse to come from 'abnormal' cyclone season with fears severe weather will return. ABC News. 2018-02-21 [2018-02-22] （澳大利亚英语）.
- ^ Moore, Sophie. Tropical Cyclone Kelvin downgraded to low. The Weekly Times. 19 February 2018 [27 February 2018].
