Tropical Storm Thelma (also known as Tropical Storm Uring in the Philippines) was the deadliest tropical cyclone in Philippine history, killing at least 5,081 people. Forming out of a tropical disturbance on November 1 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 150 mm (6 in) of rain; however, on Leyte Island there was a localized downpour that brought totals to 580.5 mm (22.85 in). 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 losing their lives along the riverbank.
Outside of Ormoc City, a further 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. 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.