Overview of Tropical Cyclones

Four tropical cyclones occurred over the western North Pacific and the South China Sea in November 2018, of which Yutu necessitated the issuance of the tropical cyclone warning signals by the Hong Kong Observatory.

Yutu which formed on 21 October moved northwards slowly on 1 November. It crossed the northeastern part of the South China Sea and weakened into a tropical storm that night. Under the influence of the dry northeast monsoon over southern China, Yutu further weakened into a tropical depression the next day and lingered over the northeastern part of the South China Sea. It finally weakened into an area of low pressure at night.

According to press reports, Yutu left at least 2 deaths and 133 injured during its passage to Saipan. Electricity supply for many places was interrupted. Yutu also brought torrential rain and squalls to the northern part of the Philippines which triggered landslides and flooding. At least 20 people were killed. For detailed information of Yutu and its impacts to Hong Kong, please refer to the tropical cyclone report of Yutu.

Toraji formed as a tropical depression over the southern part of the South China Sea about 550 km east of Ho Chi Minh City on the afternoon of 17 November. With an estimated maximum sustained wind of 55 km/h near its centre, Toraji moved northwestwards in the general direction of the southern part of Vietnam. It made landfall over the southern part of Vietnam on the afternoon of the next day and weakened into an area of low pressure rapidly.

According to press reports, at least 19 people were killed in Vietnam during the passage of Toraji.

Usagi formed as a tropical depression over the western North Pacific about 940 km east-southeast of Manila on the morning of 20 November. It tracked westwards and moved across the southern part of the Philippines. Usagi crossed the southern part of the South China Sea on 22 November. It intensified into a tropical storm the next day and turned to move on a west-southwesterly course. Usagi further intensified into a severe tropical storm on 24 November and reached its peak intensity with an estimated maximum sustained wind of 90 km/h near its centre. It changed its course to move northwestwards on 25 November. Usagi made landfall over the southern part of Vietnam during the day and weakened gradually. It finally weakened into an area of low pressure over the southern part of Vietnam on the early morning of 26 November.

According to press reports, Usagi brought torrential rain and flooding to the Philippines, causing at least one death. In Vietnam, the flooding brought by Usagi also killed at least two people.

Man-yi formed as a tropical depression over the western North Pacific about 1 420 km southeast of Guam on the night of 20 November. Tracking west-northwestwards, it intensified gradually. Man-yi developed into a typhoon on 22 November and turned to move northwards the next day, reaching its peak intensity with an estimated maximum sustained wind of 145 km/h near its centre. It moved slowly and lingered over the seas east of Luzon in the following two days. Man-yi turned to track northwestwards and weakened rapidly on 26 November, before finally weakening into an area of low pressure over the western North Pacific on the early morning of 27 November.