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Typhoon Phanfone, known in the Philippines as Typhoon Neneng, was a strong tropical cyclone which affected Japan in early October 2014. It was the eighteenth storm and the eighth typhoon of the annual typhoon season. ==Meteorological history== On September 26, a tropical disturbance began to persist approximately east of Kosrae, as well as the Japan Meteorological Agency (JMA) started to monitor the system as a low-pressure area. Late on the same day, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert (TCFA) to the flaring system as moderate vertical wind shear was being offset by widely divergent easterly outflow. However, the JTWC canceled the TCFA on the next day due to the lack of consolidation and lack of deep convection. Early on September 28, the JTWC issued a TCFA to the tropical disturbance again, as upper-level analysis indicated a marginally favorable environment with enhanced poleward outflow into the tropical upper tropospheric trough (TUTT) positioned to the north and low vertical wind shear. Several hours later, the JMA upgraded the low-pressure area to a tropical depression and started to issue tropical cyclone warnings at 21:00 UTC. At the same time, the JTWC upgraded it to a tropical depression and designate it as ''18W'', showing formative broad banding around the low-level circulation center. Early on September 29, the JTWC upgraded the system to a tropical storm, shortly before the JMA also upgraded it to a tropical storm and named it ''Phanfone''. Tracking along the southern periphery of the subtropical ridge, the storm has intensified very slowly for two days, although conditions remained favorable. Late on September 30, the JMA upgraded Phanfone to a severe tropical storm, right before the JTWC upgraded it to a typhoon. After the JMA also upgraded Phanfone to a typhoon at noon on October 1, the system started to deepen more rapidly when tracking along the southwestern periphery of a deep-layered subtropical ridge. Under low vertical wind shear and good dual channel outflow enhanced by the mid-latitude westerlies to the north, Phanfone formed a pinhole eye early on October 2. According to the JMA, Phanfone reached peak intensity with ten-minute maximum sustained winds at 175 km/h (110 mph) at 06:00 UTC, and it also became equivalent to the category 4 strength on the Saffir–Simpson hurricane wind scale.〔 Soon, the eye became cloud-filled and formed a secondary eyewall, suggesting an eyewall replacement cycle. The PAGASA named the typhoon ''Neneng'' when it entered the Philippine Area of Responsibility early on October 3. In addition, Phanfone formed a ragged and large eye, indicating the completion of the eyewall replacement cycle. Early on October 4, the JTWC upgraded Phanfone to a super typhoon when it was located about 170 km (105 mi) east-southeast of Minamidaitōjima. As the system started to tap into the mid-latitude westerlies, it was in an area of strong vertical wind shear offset by vigorous outflow, namely the improved poleward channel. Only six hours later, the JTWC downgraded Phanfone back to a typhoon owing to the loosening spiral banding. At noon, the JMA analysed that Phanfone started to weaken. The convective tops of the system intermittently warmed up afterwards, but the ragged and large eye still maintained well. Phanfone sharply recurved and accelerated northeastward early on the next day, tracking along the western edge of the deep-layered subtropical ridge. Typhoon Phanfone passed near the southern coast of Kii Peninsula around 03:00 JST on October 6 (18:00 UTC on October 5). The eye immediately dissipated, as well as the system started to undergo extratropical transition right before making landfall near Hamamatsu of the Shizuoka Prefecture in Japan after 08:00 JST (23:00 UTC on October 5). The JTWC issued the final warning to Phanfone early on October 6, and the system completely became extratropical at noon. The storm stopped weakening and began to deepen again early on October 7, and it crossed the International Date Line as a powerful extratropical cyclone early the next day.〔 Post-Tropical Cyclone Phanfone, which was located about 890 km (555 mi) southwest of Unalaska, Alaska, reached peak intensity of its extratropical period at noon on October 8, with atmosphere pressure at 948 hPa (27.99 inHg) and hurricane-force winds. The system started to weaken again early on October 9, and it turned northward early on October 11. The system eventually moved inland over Southcentral Alaska early on October 12 and dissipated later that day. 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「Typhoon Phanfone (2014)」の詳細全文を読む スポンサード リンク
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