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Tropical Storm Thelma, known in the Philippines as Tropical Storm Uring, was one of the deadliest tropical cyclones in Philippine history, killing at least 5,081 people. Forming out of a tropical disturbance on November 1, 1991, several hundred kilometers north-northeast of Palau, the depression that would become Thelma tracked generally westward. After turning southwestward in response to a cold front, the system intensified into a tropical storm on November 4 as it approached the Philippines. Hours before moving over the Visayas, Thelma attained its peak intensity with estimated ten-minute sustained winds of 75 km/h (45 mph) and a barometric pressure of 992 mbar (hPa; 29.29 inHg). Despite moving over land, the system weakened only slightly, emerging over the South China Sea on November 6 while retaining gale-force winds. Thelma ultimately succumbed to wind shear and degraded to a tropical depression. On November 8, the depression made landfall in Southern Vietnam before dissipating hours later. While passing over the Philippines, Thelma's interaction with the high terrain of some of the islands resulted in torrential rainfall. Through a process known as orographic lift, much of the Visayas received of rain; however, on Leyte Island there was a localized downpour that brought totals to . With the majority of this falling in a three-hour span, an unprecedented flash flood took place on the island. Much of the land had been deforestated or poorly cultivated and was unable to absorb most of the rain, creating a large runoff. This water overwhelmed the Anilao–Malbasag watershed and rushed downstream. Ormoc City, located past where the Anilao and Malbasag rivers converge, suffered the brunt of the flood. In just three hours, the city was devastated with thousands of homes damaged or destroyed. A total of 4,922 people were killed in the city alone, with 2,300 perishing along the riverbank. Outside of Ormoc City, 159 people were killed across Leyte and Negros Occidental. Throughout the country, at least 5,081 people lost their lives while another 1,941–3,084 were missing and presumed dead. This made Thelma the deadliest tropical cyclone in Philippine history, surpassing a storm in 1867 that killed 1,800, until later surpassed by Typhoon Haiyan (Yolanda) in 2013 which killed at least 6,300 people. A total of 4,446 homes were destroyed while another 22,229 were damaged. Total losses amounted to $27.67 million. Initially, it took over 24 hours for word of the disaster to reach officials due to a crippled communication network around Ormoc City. Within a few days, emergency supply centers were established and aid from various agencies under the United Nations and several countries flowed into the country. A total of $5.8 million worth of grants and materials was provided collectively in the international relief effort. ==Meteorological history== In late October 1991, a tropical disturbance developed near the Caroline Islands. Tracking generally west-northwestward, the system gradually became more defined. On October 31, convection associated with the system quickly increased, prompting the issuance of a Tropical Cyclone Formation Alert from the Joint Typhoon Warning Center (JTWC). Early on November 1, the Japan Meteorological Agency (JMA) began monitoring the system as a tropical depression, at which time the system was situated roughly 415 km (260 mi) north-northeast of Palau. Following a satellite-derived surface wind estimate of 45 km/h (30 mph) later that day, the JTWC also began monitoring the low as a tropical depression. Initially, forecast models showed the system continuing on an arcing path out to sea; however, the system turned westward on November 2 and threatened the Philippines.〔 Due to the cyclone's proximity to the country, the Philippine Atmospheric, Geophysical and Astronomical Services Administration also monitored the storm and assigned it with the local name ''Uring''. Late on November 3, the depression turned west-southwestward towards the Visayas in response to an approaching cold front, an event typical of late-season cyclones in the basin. On November 4, both the JTWC and JMA upgraded the system to a tropical storm, with the latter assigning it the name ''Thelma''.〔〔 Hours before striking the Philippines on November 4, both agencies reported Thelma to have reached its peak intensity. The JTWC estimated the storm to have attained one-minute sustained winds of 85 km/h (50 mph) while the JMA estimated ten-minute sustained winds at 75 km/h (45 mph). Additionally, its barometric pressure reached 992 mbar (hPa; 29.29 inHg).〔〔 Thelma soon made landfall in Samar before weakening to a minimal tropical storm. Maintaining gale-force winds, the system eventually passed over Palawan Island on November 6 before moving over the South China Sea. Despite being back over water, strong wind shear prevented re-intensification and caused Thelma to weaken to a tropical depression by November 7. Now moving westward, the depression eventually made its final landfall over the Mekong River Delta in Southern Vietnam on November 8. Within hours of moving onshore, the system dissipated.〔 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「Tropical Storm Thelma」の詳細全文を読む スポンサード リンク
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