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Severe Tropical Cyclone Rusty was a strong, slow-moving tropical cyclone that produced record duration gale-force winds in Port Hedland, Western Australia in late February 2013. Originating as an area of low pressure on 22 February well to the northwest of the Kimberley region of Western Australia, the precursor to Rusty steadily developed within a favourable environment. Gradually decreasing surface pressures in the region signaled intensification and the low was classified as ''Tropical Cyclone Rusty'' on 23 February. Although a large, sprawling system, near-record high sea surface temperatures enabled Rusty to quickly deepen. Becoming essentially stationary on 25 February, the system acquired hurricane-force winds as its core improved in structure. The cyclone achieved its peak intensity two days later with maximum ten-minute sustained winds of 165 km/h (105 mph) and a barometric pressure of 945 mbar (hPa; 27.91 inHg). Thereafter, interaction with land caused its core to collapse before the system made landfall near Pardoo Station. Rusty weakened below cyclone strength on 28 February. Its remnants persisted over Western Australia for several more days before being absorbed into an extratropical cyclone on 5 March. Owing to the slow-moving nature of Rusty, a large swath of coastal Western Australia saw heavy rains from the storm with a storm peak of at De Grey Station. Substantial flooding took place accordingly; the De Grey River crested just shy of its all-time record at . Some structural damage took place, but the predominant effects of the storm were sustained by agriculture and infrastructure. Economic losses related to the storm were estimated to be as high as A$500 million (US$480 million). The name ''Rusty'' was later retired and replaced with ''Rubina''. ==Meteorological history== In late February 2013, a monsoon trough combined with the Madden-Julian Oscillation to produce an area of low pressure on 22 February well to the northeast of the Kimberley region.〔 Upon its formation, the Bureau of Meteorology (BoM) began monitoring the system as ''Tropical Low 10U''. Low to moderate upper-level wind shear and favorable diffluence supported tropical cyclogenesis as the system moved slowly south along the edge of a subtropical ridge. By 23 February, deep convective banding features were wrapping into a well-defined circulation. This prompted the Joint Typhoon Warning Center (JTWC) to issue a Tropical Cyclone Formation Alert at 0300 UTC and subsequently initiate advisories on the storm as ''Tropical Cyclone 17S'' at 0000 UTC on 24 February. Surface pressures around the cyclone had significantly decreased by this time, with an automated weather station on Rowley Shoals, roughly 130 km (80 mi) southeast of the storm's centre, recording a 7 mbar (hPa; 0.21 inHg) drop to 993 mbar (hPa; 29.33 inHg) in 24 hours.〔 The BoM similarly classified the system as a tropical cyclone hours later as gale-force winds were observed on Bedout Island. They consequently assigned it the name ''Rusty'', at which time the cyclone was situated roughly north of Port Hedland, Western Australia.〔 A large monsoonal cyclone,〔 Rusty featured an expansive cloud mass with a relatively cloud-free centre spanning 160 km (100 mi). Under normal circumstances, cyclones of this nature tend to develop slowly due to their sprawling nature; however, near-record high sea surface temperatures of fueled an unusually quick organization. The high temperatures were linked to a record warm January across the entirety of Australia. Additionally the warmth extended to a great depth, resulting in a high tropical cyclone heat potential of 90 kJ/cm2. Throughout 24 February, convective bands steadily consolidated around the circulation as it intensified. The strongest winds continued to be displaced well to the south of the centre, however, within the most persistent convective band. This large, intense band extended westward from Broome to Port Hedland and into the western portion of Rusty's circulation. Areas within this band experienced gale-force winds despite being more than away from the cyclone. Increasingly rapid strengthening took place later in the day with a 35 km (25 mi) wide eye developing. Rusty became virtually stationary late on 25 February as a trough to its south weakened the ridge previously steering the cyclone south. Throughout 25 February, the storm's eye expanded to an asymmetrical 95 by 185 km (60 by 115 mi) diameter. By 1200 UTC, Rusty had intensified into a severe tropical cyclone — a Category 3 or higher on the Australian cyclone intensity scale; this was supported by measurements of sustained at Rowley Shoals. The large circulation began contracting later that day and into 26 February. Intensification resumed later that day and into 27 February. Favorable outflow, enhanced by a mid-latitude trough to the south, allowed for deep convection to form around the eyewall.〔 Rusty attained its peak strength early on 27 February with sustained winds of 165 km/h (105 mph), with gusts up to 230 km/h (145 mph), and an estimated central pressure of 945 mbar (hPa; 27.91 inHg).〔 The JTWC estimated one-minute sustained winds at this time to have been 185 km/h (115 mph), equivalent to a Category 3 hurricane on the Saffir–Simpson hurricane wind scale. Shortly thereafter, the ridge over Australia began to rebuild and prompted Rusty to drift south-southeast. Interaction with the Australian mainland incited weakening of the cyclone.〔 As it approached the Pilbara coastline, the eastern eyewall collapsed and its eye became increasingly cloud-filled. Bedout Island, which took a direct hit from the eyewall, only recorded sustained winds with gusts to . Around 0900 UTC on 27 February Rusty made landfall near Pardoo Station, roughly 110 km (70 mi) east of Port Hedland, with winds of 130 km/h (80 mph).〔 Once onshore, steady weakening ensued. Within six hours, the eye dissipated and deep convection diminished, becoming more confined to the southern side of the circulation. A combination of increasing shear and land interaction ultimately caused the storm to weaken below cyclone strength early on 28 February, at which time it was situated roughly southeast of Nullagine.〔 The remnants continued southward over Western Australia, eventually opening up into a trough on 3 March. The system subsequently moved back over water that day before being absorbed by an approaching extratropical cyclone by 5 March. 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 Rusty」の詳細全文を読む スポンサード リンク
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