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Very Intense Tropical Cyclone Gafilo ((:ɡafil); also known as Cyclone Gafilo) was the most intense tropical cyclone ever recorded in the South-West Indian Ocean. Being unusually large and violent, Gafilo was the deadliest and most destructive cyclone of the 2003–04 season. Gafilo killed at least 237 people and caused about $250 million (2004 USD) in Madagascar, making it the most devastating storm to the island country on reliable record. Forming south of Diego Garcia, it intensified into a moderate tropical storm on 3 March. One day later, Gafilo became a tropical cyclone, and it ultimately intensified into a very intense tropical cyclone on 6 March, prior to making landfall over Madagascar early on the next day. After crossing the island, Gafilo emerged into the Mozambique Channel and made landfall over Madagascar again on 9 March. After a three-day loop overland, the system arrived at the Indian Ocean on 13 March, and it transitioned into a subtropical depression on 14 March. ==Meteorological history== A disturbance formed south of Diego Garcia on 29 February, and Météo-France La Réunion (MFR) upgraded the identified system within the monsoon trough to a tropical disturbance on the next day. On 2 March, although the centre was exposed due to moderate easterly vertical wind shear, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert on the system which was situated north of a subtropical ridge, based on improved organisation of deep convection and moderate poleward outflow. However, its temporary acceleration on that day lessened vertical wind shear. As the centre became under organised deep convection on 3 March, the system intensified into a tropical depression, then a moderate tropical storm named ''Galifo'' by the Sub-regional Tropical Cyclone Advisory Centre in Mauritius, shortly before MFR even upgraded Gafilo to a severe tropical storm later. When the system slowed down and tracked west-northwestwards along the northern periphery of a building subtropical ridge, it reached category 1 strength on the Saffir–Simpson hurricane wind scale late on 3 March. Although dry air significantly reduced deep convection on 4 March, MFR upgraded Gafilo to a tropical cyclone because of a banding eye, when the system began to expand its clockwise circulation and track west-southwestwards. By duel outflow channels, Gafilo underwent rapid deepening and reached category 4 strength on the Saffir–Simpson hurricane wind scale on 5 March, as MFR also upgraded Gafilo to an intense tropical cyclone late on the same day. On 6 March, beside warm sea surface temperature above 29 °C, the atypically third outflow channel from the west made conditions more favourable. Therefore, MFR upgraded Gafilo to a very intense tropical cyclone with a very well-defined circular and warm diameter eye at 06Z, when it also reached category 5 strength on the Saffir–Simpson hurricane wind scale. At 12Z, Gafilo attained its peak intensity by the ten-minute maximum sustained winds reaching 125 knots (230 km/h, 145 mph) and the atmospheric pressure decreasing to , although microwave imagery showed that the eyewall replacement cycle had begun. Shortly after slightly weakening due to land interaction, Gafilo made landfall in vicinity of Antalaha, Madagascar early on 7 March. Unlike other storms, the overland depression just weakened gradually, because of its unusually large circulation making the outer part still at sea. On that day, Gafilo tracked more southwestwards along the northwestern periphery of a subtropical ridge located to the southeast. Before noon on 8 March, Gafilo arrived at the Mozambique Channel as a moderate tropical storm which strongest winds were located in the northern sector. On 9 March, Gafilo became almost stationary and then tracked southeastwards along the western periphery of a subtropical ridge located to the east. MFR upgraded the system to a severe tropical storm supported by observed data from Malagasy stations at noon; however, JTWC analysed that the storm became below category 1 strength on the Saffir–Simpson hurricane wind scale at the same time in their best track data. Late on 9 March, Gafilo made landfall north of Morombe, Madagascar, and the system started to make a three-day clockwise loop over the south part of Madagascar.〔 For the system further weakened after landfall, JTWC analysed that Gafilo dissipated overland late on 11 March, as well as MFR issued a final warning on the overland depression which began to track southeastwards early on 12 March. Surprisingly, MFR began to issue warnings again to the completely disorganised system at noon on 12 March, as the residual centre was expected to go back overseas. Late on the same day, JTWC issued a Tropical Cyclone Formation Alert on the overland remnants, because of improved deep convection over the low-level circulation centre, poleward outflow and weak vertical wind shear. Early on 13 March, Gafilo arrived at the Indian Ocean as a tropical disturbance, yet JTWC cancelled a Tropical Cyclone Formation Alert on the system because of the less organised low-level circulation centre and moderate vertical wind shear. Gafilo transferred into a subtropical depression south of La Réunion on 14 March, when the deep convective activity was intensifying with better organisation of a small cluster above the low-level circulation centre due to good upper-level divergence and warm sea surface temperature of 26 °C to 29 °C. After attaining minor peak intensity of its subtropical period late on 14 March, Gafilo began to track eastwards and transferred into an extratropical depression on 15 March. Owing to a building subtropical ridge located to the southwest, the extratropical depression slowed down and turned northwestwards on 16 March. After slowly weakening, the system completely dissipated on 18 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 Gafilo」の詳細全文を読む スポンサード リンク
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