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Severe Tropical Cyclone Monica was the most intense tropical cyclone, in terms of maximum sustained winds, on record to impact Australia. The 17th and final storm of the 2005–06 Australian region cyclone season, Monica originated from an area of low pressure off the coast of Papua New Guinea on 16 April 2006. The storm quickly developed into a Category 1 cyclone the next day, at which time it was given the name Monica. Travelling towards the west, the storm intensified into a severe tropical cyclone before making landfall in Far North Queensland, near Lockhart River, on 19 April 2006. After moving over land, convection associated with the storm quickly became disorganised. On 20 April 2006, Monica emerged into the Gulf of Carpentaria and began to re-intensify. Over the following few days, deep convection formed around a wide eye. Early on 22 April 2006, the Bureau of Meteorology (BoM) assessed Monica to have attained Category 5 status, on the Australian cyclone intensity scale. The Joint Typhoon Warning Center (JTWC) also upgraded Monica to a Category 5 equivalent cyclone, on the Saffir–Simpson Hurricane Scale. The storm attained its peak intensity the following day with winds of 250 km/h (155 mph 10-minute winds) and a barometric pressure of 916 mbar (hPa; 27.05 inHg). On 24 April 2006, Monica made landfall about west of Maningrida, at the same intensity. Rapid weakening took place as the storm moved over land. Less than 24 hours after landfall, the storm had weakened to a tropical low. The remnants of the former-Category 5 cyclone persisted until 28 April 2006 over northern Australia. In contrast to the extreme intensity of the cyclone, relatively little structural damage resulted from it. No injuries were reported to have occurred during the storm's existence and losses were estimated to be A$6.6 million (US$5.1 million). However, severe environmental damage took place. In the Northern Territory, an area about 7,000 km2 (4,300 mi2) was defoliated by Monica's high wind gusts. In response to the large loss of forested area, it was stated that it would take several hundred years for the area to reflourish. ==Meteorological history== Severe Tropical Cyclone Monica originated from an area of low pressure that formed early on 16 April 2006 off the coast of Papua New Guinea.〔 The low quickly became organised, with deep convection developing over the low-pressure centre. Later that day, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert as the system became increasingly organised. Early the next day, the Bureau of Meteorology in Brisbane, Australia declared that the low had developed into a Category 1 cyclone on the Australian tropical cyclone scale, with winds reaching 65 km/h (40 mph 10-minute sustained). Upon being classified as a cyclone, the storm was given the name Monica. At the same time, the JWTC designated Monica as Tropical Cyclone 23P. Monica tracked generally westward, towards Far North Queensland, in response to a low to mid-level ridge to the south. Low wind shear and good divergence in the path of the storm allowed for continued intensification as continued westward. Late on 17 April 2006, Monica intensified into a Category 2 Cyclone, with winds reaching 95 km/h (60 mph 10-minute sustained).〔〔 By 1200 UTC on 18 April 2006, the Bureau of Meteorology upgraded Monica to a severe tropical cyclone, a Category 3 on the Australian scale.〔 This followed an increase in the storm's outflow and a fluctuating central dense overcast. Several hours later, the JTWC upgraded Monica to the equivalent of a Category 1 hurricane on the Saffir–Simpson Hurricane Scale.〔 During the afternoon of 19 April 2006, the storm made landfall roughly south-southeast of the Lockhart River with winds of 130 km/h (80 mph 10-minute sustained).〔〔 At the same time, the JTWC assessed Monica to have intensified into a Category 2 equivalent storm with winds of 155 km/h (100 mph 1-minute sustained).〔 Shortly after making landfall, convection associated with the storm deteriorated and the outflow became fragmented. A shortwave trough to the south caused the ridge steering Monica to weaken, leading to the cyclone moving slower. After moving over land, the storm began to weaken, with the Bureau of Meteorology downgrading the storm to weaken to Category 1 cyclone〔 and the JTWC downgraded the cyclone to a tropical storm.〔 The following day, Monica moved offshore, entering the Gulf of Carpentaria. Once back over water, favourable atmospheric conditions allowed the storm to quickly intensify.〔 Within 24-hours of moving over water, Monica re-attained severe tropical cyclone status.〔 Following a shift in steering currents, the storm slowed significantly and turned north-westward.〔 Steady intensification continued through 22 April 2006 as the storm remained in a region of low wind shear and favourable diffluence. Early on 22 April 2006 the Bureau of Meteorology upgraded Monica to a Category 5 severe tropical cyclone, the third of the season.〔〔 By this time, a wide eye had developed within the central dense overcast of the cyclone. Later that day, the JTWC assessed Monica to have intensified into a Category 5 equivalent storm.〔 Cyclone Monica attained its peak intensity on 23 April 2006 near Cape Wessel with a barometric pressure 916 mbar (hPa; 27.05 inHg). Maximum winds were estimated at 250 km/h (155 mph 10-minute sustained) by the Bureau of Meteorology〔〔 while the JTWC assessed it to have attained winds of 285 km/h (180 mph 1-minute sustained).〔 Using the Dvorak technique, the peak intensity of the cyclone was estimated at T-number of 7.5 according to the Satellite Analysis Branch (SAB), yet the Advanced Dvorak Technique of the CIMSS automatically estimated at T8.0, the highest ranking on the Dvorak Scale.〔 However, since the JTWC, SAB and CIMSS are not the official warning centres for Australian cyclones, these intensities remain unofficial. On 24 April 2006, the mid-level ridge south of Monica weakened, causing the storm to turn towards the south-west.〔 Following this, the storm made landfall in the Northern Territory, roughly west of Maningrida, as a Category 5 cyclone with winds of 250 km/h (155 mph 10-minute sustained).〔 Not long after making landfall, the storm weakened extremely quickly. Most convective activity associated with the storm dissipated within nine hours of moving onshore. This resulted in the storm's maximum winds decreasing by 155 km/h (100 mph) in a 12-hour span.〔 After this rapid weakening, the storm turned sharply west moving over the town of Jabiru as a Category 2 cyclone. Within six hours of passing this town, the Bureau of Meteorology downgraded Monica to a tropical low, no longer producing gale-force winds.〔 The JTWC issued their final advisory on the storm at 1800 UTC that day. The remnants of Monica persisted for several more days, tracking near Darwin on 25 April 2006 before turning south-east and accelerating over the Northern Territory. The remnants eventually dissipated on 28 April 2006 over central Australia.〔 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 Monica」の詳細全文を読む スポンサード リンク
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