Report on Typhoon Toraji (2423)
Typhoon Toraji (2423)
9 – 15 November 2024
Toraji was the sixth tropical cyclone affecting Hong Kong in 2024. During the passage of Toraji, the Observatory issued the No. 8 Gale or Storm Signal on the night of 13 November, the latest issuance of No. 8 Gale or Storm Signal in a year since 1946.
Toraji formed as a tropical depression over the western North Pacific about 1 270 km east of Manila on the morning of 9 November. It then moved west to west-northwestwards towards Luzon and intensified into a tropical storm that night. Toraji intensified progressively into a typhoon the next day and attained its peak intensity over the coastal waters east of Luzon with an estimated maximum sustained wind of 130 km/h near its centre on the morning of 11 November. Toraji moved across Luzon during the day that day and gradually turned to move northwestwards and entered the central part of the South China Sea that evening. Toraji moved towards the coast of Guangdong and weakened gradually into tropical storm in the following two days. It turned to move westwards slowly across the seas south of Hong Kong on the morning of 14 November. Toraji finally degenerated into an area of low pressure over the seas south of Shangchuan Dao on the morning of 15 November.
According to press reports, Toraji brought heavy rain and squalls to the Philippines, leading to flooding in many places and many casualties.
The Standby Signal No. 1 was issued at 10:20 p.m. on 11 November, when Toraji was about 730 km southeast of Hong Kong. Local winds were moderate northeasterlies and occasionally fresh offshore the next day and on the morning of 13 November. With Toraji edging closer to the coast of Guangdong, the No. 3 Strong Wind Signal was issued at 2:40 p.m. on 13 November, when Toraji was about 230 km southeast of Hong Kong. Under the combined effect of Toraji and the northeast monsoon, winds over Hong Kong strengthened gradually later that day and were fresh to strong north to northeasterlies, occasionally reaching gale force on high ground.
As Toraji further approached the vicinity of the Pearl River Estuary that night, the radar imagery (Figure 6) revealed that the gale force winds associated with Toraji were rather close to Hong Kong and were expected to pose a threat to the territory. Thus, the No. 8 Northeast Gale or Storm Signal was issued at 11:10 p.m. on 13 November when Toraji was about 160 km south-southeast of Hong Kong. Local winds strengthened further that night and the next morning, with strong to gale force northeasterlies affecting most parts of the territory.
Toraji came closest to Hong Kong at around 5 a.m. on 14 November, when it skirted past about 130 km south of the territory. Toraji moved westwards slowly across the seas south of Hong Kong that morning. With Toraji weakening and the area of its associated gale force winds diminishing, the No. 8 Northeast Gale or Storm Signal was replaced by the No. 3 Strong Wind Signal at 10:20 a.m. on 14 November. Strong east to northeasterlies continued to prevail locally during the day. As Toraji continued to weaken and move further away from Hong Kong that night, local winds moderated gradually. The No. 3 Strong Wind Signal was replaced by the No.1 Standby Signal l at 10:20 p.m. on 14 November and all tropical cyclone warning signals were cancelled at 1:20 a.m. on 15 November.
Under the influence of Toraji, maximum hourly mean winds of 73, 70 and 60 km/h and gusts of 93, 102 and 80 km/h were recorded at Waglan Island, Ngong Ping and Cheung Chau Beach respectively. A maximum sea level (above chart datum) of 2.86 m was recorded at Tsim Bei Tsui and a maximum storm surge (above astronomical tide) of 0.65 m was recorded at Tai Po Kau. The lowest instantaneous mean sea-level pressures recorded at some selected stations are as follows:
| Station | Lowest instantaneous mean sea-level pressure (hPa) |
Date/Month | Time |
|---|---|---|---|
| Hong Kong Observatory Headquarters | 1007.8 | 14/11 | 3:29 a.m. |
| Hong Kong International | 1007.9 | 14/11 | 2:08 p.m. |
| Cheung Chau | 1007.6 | 14/11 | 3:28 a.m. |
| King’s Park | 1007.8 | 14/11 | 4:15 a.m. |
| Lau Fau Shan | 1008.3 | 14/11 | 1:38 p.m. |
| Peng Chau | 1007.7 | 14/11 | 3:56 a.m. |
| Sha Tin | 1008.1 | 14/11 | 3:58 a.m. |
| Sheung Shui | 1008.3 | 14/11 | 1:38 p.m. |
| Ta Kwu Ling | 1008.3 | 14/11 | 3:18 a.m. |
| Tai Po | 1009 | 14/11 | 3:25 a.m. |
| Waglan Island | 1006.7 | 14/11 | 4:13 a.m. |
While there were a few isolated showers at first on 11 November, the weather turned mainly fine that afternoon and the next day. With the approach of Toraji, the weather of Hong Kong deteriorated with more showers on 13 November. The outer rainbands of Toraji brought squally showers to Hong Kong on 14 November. Also under the influence of the remnant of Toraji, the weather remained cloudy with occasional rain on 15 November. More than 30 millimetres of rainfall were generally recorded over the territory and rainfall even exceeded 70 millimetres over parts of Sha Tin and Tai Po Districts on 14 – 15 November.
In Hong Kong, one person was injured and there were at least 227 reports of fallen trees during the passage of Toraji.