Overview of Tropical Cyclone in July 2024

Three tropical cyclones occurred over the western North Pacific and the South China Sea in July 2024. Among them, Prapiroon necessitated the issuance of the tropical cyclone warning signal by the Observatory.

A tropical depression formed over the southern part of the South China Sea about 570 km east-southeast of Da Nang on the evening of 13 July, with an estimated maximum sustained wind of 45 km/h near its centre. It generally tracked northwestwards in the following two days and finally weakened into an area of low pressure over the central part of Vietnam on the night of 15 July.

Prapiroon formed as a tropical depression over the central part of the South China Sea about 630 km east-southeast of Xisha on the afternoon of 19 July and moved west-northwestwards across the central part of the South China Sea. It intensified into a tropical storm on the morning of 21 July and turned to move north-northwestwards towards Hainan Island. Before making landfall over Hainan Island, Prapiroon further intensified into a severe tropical storm that night. Prapiroon made landfall over Wanning, Hainan in the small hours of 22 July and weakened slightly into a tropical storm as it moved across Hainan Island. Prapiroon re-intensified into a severe tropical storm as it moved across Beibu Wan. It attained its peak intensity with an estimated maximum sustained wind of 105 km/h near its centre on the evening of 22 July. Prapiroon made landfall over the northern part of Vietnam on the morning of 23 July. It then moved inland and weakened gradually. Prapiroon finally degenerated into an area of low pressure that night.

According to press reports, Prapiroon brought torrential rain and squalls to Hainan Island, resulting in fallen trees in many parts of the region and an interruption in electricity supply to over 220 000 households. For detailed information of Prapiroon including its impact to Hong Kong, please refer to the Tropical Cyclone Report of Prapiroon.

Gaemi formed as a tropical depression over the western North Pacific about 1 090 km east of Manila on the night of 19 July. It moved northwestwards or west-northwestwards across the seas east of the Philippines and intensified gradually. Gaemi turned to move generally northwards towards the seas east of Taiwan on 22 July and intensified into a typhoon that night. It then turned to move northwestwards towards Taiwan in the next evening. On 24 July, Gaemi intensified into a super typhoon and attained its peak intensity with an estimated maximum sustained wind of 195 km/h near its centre. Affected by Taiwan’s terrain, Gaemi lingered around the coastal waters east of Taiwan and made an anti-clockwise loop that night. Gaemi weakened into a severe typhoon when it moved across Taiwan in the small hours of 25 July. It made landfall over Putian, Fujian that night and further weakened into a severe tropical storm. In the following two days, Gaemi moved generally northwestwards or west-northwestwards into inland and continued to weaken. It finally degenerated into an area of low pressure over Hubei on the morning of 28 July.

According to press reports, Gaemi, together with the southwest monsoon, brought days of torrential rain and squalls to the Philippines. At least 53 people were found dead or missing, and 16 were injured. More than 6.4 million people were affected. More than 8 500 houses were damaged and the economic loss exceeded PHP 9.2 billion in the Philippines. A 24-hour rainfall of 1 217.5 millimetres was recorded in Maolin of Gaoxiong during the passage of Gaemi over Taiwan. Torrential rain and squalls left at least 12 dead or missing, and more than 900 injuries. Water and electricity supply to more than 160 000 and 870 000 households were disrupted respectively. The economic loss exceeded USD 110 million. More than 1.47 million people were affected in Fujian, Zhejiang, Jiangxi and Guangdong with the economic loss exceeding RMB 5.7 billion. In addition, affected by the remnant of Gaemi, Hunan reported a record-breaking 24-hour rainfall of 642.5 millimetres. The torrential rain left 94 dead or missing. More than 1.21 million people were affected and the economic loss exceeded RMB 8.6 billion.