Pakhar was the fourth tropical cyclone affecting Hong Kong and necessitating the issuance of the No. 8 Gale or Storm Signal in 2017.
Pakhar formed as a tropical depression over the western North Pacific about 570 km east of Manila on the night of 24 August. Moving generally westwards at first, it developed into a tropical storm the next day and moved northwestwards across Luzon. After entering the South China Sea on the morning of 26 August, Pakhar maintained a northwestward track and accelerated towards the coast of Guangdong. It intensified into a severe tropical storm during the night, reaching its peak intensity with an estimated sustained wind of 110 km/h near its centre. After making landfall over the coast of western Guangdong in the vicinity of Zhuhai and Taishan on the morning of 27 August, Pakhar weakened gradually and dissipated over Guangxi that night.
According to press reports, Pakhar and its remnant brought heavy rain and squalls to Guangdong, Guangxi, Guizhou and Yunnan, resulting in at least 12 deaths. Around 100 000 people were affected with direct economic loss around 370 million RMB. In Macao, eight people were injured and many places were flooded during the passage of Pakhar. A cargo vessel sunk about 120 km east of Hong Kong and 11 crew members on board were rescued.
In Hong Kong, the No. 1 Standby Signal was issued at 9:40 a.m. on 26 August when Pakhar was about 730 km southeast of the territory. Moderate easterlies affected Hong Kong during the day. As Pakhar edged closer to the coast of Guangdong, the No. 3 Strong Wind Signal was issued at 8:40 p.m. that night when Pakhar was about 360 km south-southeast of Hong Kong. Local winds gradually became fresh to strong northeasterly during the night and occasionally reached gale force offshore. As Pakhar moved quickly towards the Pearl River Estuary, local winds continued to strengthen and the No. 8 Southeast Gale or Storm Signal was issued at 5:10 a.m. on 27 August when Pakhar was about 80 km south of the Hong Kong Observatory. Gale to storm force winds generally affected the territory around dawn, occasionally reaching hurricane force on high ground and with wind direction gradually veering from northeasterly to southeasterly. Pakhar came closest to Hong Kong around 7 a.m. that morning with its centre passing only about 70 km southwest of the Hong Kong Observatory. With Pakhar moving into inland Guangdong, local winds started to weaken later that day and the No. 3 Strong Wind Signal and No. 1 Standby Signal were issued at 1:40 p.m. and 5:40 p.m. respectively. Pakhar dissipated over Guangxi during the night and all tropical cyclone warning signals were cancelled at 10:10 p.m.
Under the influence of Pakhar, maximum hourly mean winds of 118, 103 and 101 km/h and gusts of 173, 146 and 155 km/h were recorded at Ngong Ping, Tai Mei Tuk and Cheung Chau respectively. A maximum sea level (above chart datum) of 2.63 m was recorded at Tsim Bei Tsui, and a maximum storm surge (above astronomical tide) of 1.05 m was recorded at Tai Po Kau. The lowest instantaneous mean sea-level pressures recorded at some selected stations are as follows:
Locally, it was mainly fine and very hot during the day on 26 August. Showers set in at night under the influence of the rainbands associated with Pakhar. Heavy rain with squalls and thunderstorms affected the territory on 27 and 28 August, and Amber Rainstorm Warnings were issued by the Observatory in the morning on both days. More than 250 millimetres of rainfall were recorded over most part of the territory during the 3-day period.
In Hong Kong, at least 62 people were injured during the passage of Pakhar. There were more than 2,000 reports of fallen trees, 16 reports of flooding and one report of landslide. Some scaffolding in Sai Wan and Kowloon City collapsed. Two hikers were hurt and stranded on Kowloon Peak and had to be rescued by firemen. One fireman was injured during the rescue operation. Many roads were flooded during the rainstorms on the mornings of 27 and 28 August. Fallen trees near the University Station of the East Rail Line resulted in a disruption of train services. More than 670 flights were cancelled or delayed at the Hong Kong International Airport, and 50 flights were diverted.