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Typhoon Sarah, known in the Philippines as Typhoon Openg, was a powerful typhoon that caused extensive damage along an erratic path across the Western Pacific in September 1989. Originating from a disturbance within a monsoon trough in early September, Sarah was first classified as a tropical depression near the Mariana Islands on September 5. Moving quickly westward, the depression soon strengthened into Tropical Storm Sarah. On September 8, the storm abruptly turned southward and temporarily attained typhoon status. Following a series of interactions with secondary areas of low pressure, the storm turned northward the following day. By September 11, Sarah entered a region favoring development and underwent a period of explosive intensification. At the end of this phase, the storm attained its peak intensity as a Category 4–equivalent typhoon on the Saffir–Simpson Hurricane Scale. The typhoon subsequently weakened rapidly and made two landfalls in Taiwan by September 12. After moving over the Taiwan Strait, Sarah made its final landfall in Eastern China on September 13 before dissipating the following day. While the typhoon meandered near the Philippines, it brought several days of heavy rain to much of Luzon, triggering extensive flash flooding. At least 44 people perished across the country and another 200,000 were left homeless. Striking Taiwan as a strong typhoon, Sarah caused widespread wind damage that left approximately 840,000 residents without power. Excessive rainfall associated with the storm triggered flooding that washed away highways and inundated about 40,500 hectares (100,000 acres) of farmland. Throughout the island, Sarah was responsible for 19 fatalities and at least $171 million USD (4.38 billion New Taiwan dollars) in damage. Four deaths also took place on the Gotō Islands. Additionally, four deaths took place offshore and another seventeen people were listed as missing. ==Meteorological history== In early September 1989, a monsoon trough became established across the western Pacific. By September 3, a disturbance formed within the trough approximately 1,100 km (685 mi) southeast of the Japanese island of Minamitorishima. Initially, a tropical upper tropospheric trough (TUTT) to the northwest inhibited convective development; however, "complex interactions", according to Lt. Cdr. Nicholas D. Gural, later occurred between the TUTT cell, the initial disturbance, and a second disturbance, which resulted in favorable conditions for tropical cyclogenesis. Due to the improved environment, the Joint Typhoon Warning Center (JTWC) issued two Tropical Cyclone Formation Alerts on the system on September 5.〔 By this time, the Japan Meteorological Agency (JMA) began monitoring the system as a tropical depression. Ultimately, the JTWC issued their first advisory on Tropical Depression 22W early on September 6, at which time the depression was situated northwest of the Mariana Islands. Initially, the depression tracked west-southwestwards and gradually intensified; however, after being upgraded to Tropical Storm Sarah late on September 6, the system turned northwestward and accelerated towards Okinawa. By September 8, Sarah decelerated as it underwent a binary interaction with a secondary area of convection to the southwest. This interaction caused the cyclone to abruptly turn southwestward towards the Philippines before nearly stalling on September 9. During this time, the storm temporarily attained typhoon status, having estimated winds of 120 km/h (75 mph). Coinciding with Sarah's time as a typhoon, a new area of low pressure, classified as a "lee side low", developed along the west coast of Luzon.〔 Due to the cyclone's proximity to the Philippines, the Philippine Atmospheric, Geophysical and Astronomical Services Administration also monitored the storm and assigned it with the local name ''Openg''.〔 Later on September 9, Sarah turned sharply northward as the lee side low rapidly tracked northeast. Reintensification gradually took place as the storm moved away from the Philippines, with the storm reaching typhoon status by September 10. Tracking generally towards the north-northwest, Sarah entered a favorable region for development and underwent a period of explosive intensification on September 11. Over a six hour span, the storm's winds increased from 140 km/h (85 mph) to 215 km/h (135 mph). A powerful typhoon, Sarah featured a well-defined eye and multiple outflow channels. The storm reached its peak strength later that day as a Category 4–equivalent typhoon on the Saffir–Simpson Hurricane Scale with winds of 230 km/h (145 mph).〔 The JMA assessed Sarah to have been somewhat weaker, estimating peak ten-minute sustained winds of 150 km/h (90 mph) along with a barometric pressure of 950 mbar (hPa; 28.05 inHg).〔 Forecasters at the JTWC initially projected the storm to track north of Taiwan on September 12 and merge with an approaching frontal system. Contrary to this, Sarah moved south of the expected path and quickly weakened as it interacted with the mountainous terrain of Taiwan. The storm eventually struck the island with winds of 165 km/h (105 mph) late on September 11. Unexpectedly, the typhoon executed a counterclockwise loop and briefly moved offshore before making a second landfall 12 hours later along the northeastern coast of Taiwan as a tropical storm. Sarah failed to reorganize as it moved over the Taiwan Strait and later made its final landfall in Zhejiang, China as a minimal tropical storm on September 13. The storm was last noted the following day as dissipating over Eastern China.〔 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 Sarah (1989)」の詳細全文を読む スポンサード リンク
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