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Typhoon Francisco, known in the Philippines as Typhoon Urduja, was a powerful typhoon that strengthened to the equivalent of a Category 5 on the Saffir-Simpson scale, according to the Joint Typhoon Warning Center. The 25th named storm and the 10th typhoon of the 2013 Pacific typhoon season, Francisco formed on October 16 east of Guam from a pre-existing area of convection. With favorable conditions, it quickly intensified into a tropical storm before passing south of Guam. After stalling to the southwest of the island, Francisco turned to the northwest into an environment of warm waters and low wind shear, becoming a typhoon. The JTWC upgraded it to super typhoon status on October 18, while the Japan Meteorological Agency (JMA) estimated peak 10 minute sustained winds of 195 km/h (120 mph). Gradual weakening ensued, and after the typhoon turned to the northeast, Francisco deteriorated into a tropical storm on October 24. Passing southeast of Okinawa and mainland Japan, the storm accelerated and became extratropical on October 26, dissipating later that day. On Guam and in the Northern Marianas Islands, Francisco produced tropical storm force wind gusts, strong enough to knock over some trees and cause $150,000 (2013 USD) in damage. The typhoon also dropped heavy rainfall on Guam, peaking at 201 mm (7.90 in) at Inarajan. Later, Francisco brought gusty winds and some rainfall to Okinawa. In Kagoshima Prefecture, 3,800 homes lost power, while an island-wide evacuation advisory was issued for Izu Ōshima after Typhoon Wipha spawned a deadly mudslide a week prior. Rains in Japan peaked at in Niyodogawa, Kōchi on Shikoku. ==Meteorological history== Early on October 15, an area of convection persisted about 750 km (465 mi) east-northeast of Guam. Initially the system was located within an area of moderate wind shear, although conditions gradually became more favorable for tropical cyclogenesis.〔(【引用サイトリンク】date=2013-10-15 )〕 At 12:00 UTC on October 15, the Japan Meteorological Agency (JMA) estimated that a tropical depression developed about 450 km (280 mi) east of Guam. A few hours later, the Joint Typhoon Warning Center (JTWC) issued a tropical cyclone formation alert before initiating advisories on Tropical Depression ''26W'' early on October 16. At that time, the depression was passing about 100 km (65 mi) southeast of Guam. After formation, the system moved west-southwestward under a ridge to the north. Its circulation consolidated as the thunderstorm activity organized, aided by warm sea surface temperatures and decreasing wind shear.〔 At 06:00 UTC on October 16, the JMA upgraded the depression to Tropical Storm ''Francisco (1327)''.〔 As a quickly organizing tropical cyclone, Francisco developed an eye feature late on October 16 in the center of the convection, as outflow improved and an anticyclone formed aloft. Based on the improved structure, the JMA upgraded Francisco to a severe tropical storm at 18:00 UTC on October 16, followed by upgrading it to typhoon status at 06:00 UTC the next day.〔 Francisco slowed its forward motion as steering currents weakened,〔 with a north-northwest drift beginning on October 17 due to an extension of the subtropical ridge.〔 By later that day, the typhoon had a well-defined eye 28 km (17 mi) across and surrounded by deep convection, while passing west of Guam and the Northern Marianas Islands. The track accelerated more to the northwest, steered by the strengthening ridge. With the eyewall convection become more distinct, Francisco continued to intensify, and the JTWC upgraded it to a super typhoon on October 18. At 18:00 UTC, the JMA estimated the typhoon attained peak 10 minute sustained winds of 195 km/h (120 mph).〔 On October 19, the JTWC upgraded Francisco to peak 1 minute winds of 260 km/h (160 mph), the equivalent of a Category 5 on the Saffir-Simpson scale; by that time, the eyewall contracted to just 19 km (12 mi) in diameter. After maintaining its peak intensity for about 36 hours, Francisco began weakening,〔 after the eye lost definition due to building wind shear. By October 21, the eye became ragged and cloud-filled while the overall satellite presentation of the storm became elongated. That day, the typhoon entered the area of responsibility of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), which gave Francisco the local name ''Urduja''; the agency would cease issuing advisories on October 23. Conditions generally remained favorable, allowing the eye to remain distinct despite a great reduction in the sustained winds. Dry air began affecting the tropical cyclone late on October 22, cutting off the flow of moist air, and water temperatures cooled along the storm's track. As a result, the eye dissipated and the convection weakened. An approaching trough from the Korean peninsula weakened the ridge to the north, slowing the typhoon and allowing it to turn north and northeast on October 24. Francisco weakened below typhoon status after passing 210 km (130 mi) southeast of Okinawa.〔 The storm began interacting with the approaching cold front while it passed south of Japan, moving around the subtropical ridge. With increasing wind shear, the circulation became exposed from the convection, and the JTWC discontinued advisories on October 25, declaring that Francisco was becoming extratropical. On the next day, Francisco completed its extratropical transition, but dissipated later on October 26, to the southeast of Japan.〔 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 Francisco (2013)」の詳細全文を読む スポンサード リンク
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