Report on Typhoon Nesat (2220)

Nesat was the fifth tropical cyclone affecting Hong Kong in 2022.

Nesat formed as a tropical depression over the western North Pacific about 800 km northeast of Manila in the small hours on 15 October. It moved westwards towards Luzon Strait and intensified gradually. Nesat entered the northern part of the South China Sea and developed into a typhoon on the afternoon of the next day. It turned to move west-southwestwards towards the vicinity of Xisha on 17 October. Nesat reached its peak intensity on that night with an estimated maximum sustained wind of 145 km/h near its centre. Under the influence of the northeast monsoon, it weakened gradually in the following three days and finally degenerated into an area of low pressure over the central part of the South China Sea to the southwest of Hainan Island on 20 October.

The Standby Signal No. 1 was issued at 9:20 p.m. on 16 October, when Nesat was about 530 km east-southeast of Hong Kong. Local winds were fresh northerlies and occasionally strong offshore and on high ground overnight. As Nesat intensified gradually and continued to edge closer to the coast of southern China, the No. 3 Strong Wind Signal was issued at 11:30 a.m. on 17 October when Nesat was about 400 km southeast of Hong Kong. Under the combined effect of the northeast monsoon and Nesat, local winds were generally strong northerlies and occasionally reached gale force on high ground. Nesat came closest to Hong Kong at around 5 p.m. on 17 October, skirting past about 380 km south-southeast of the territory. With Nesat weakening and moving away from Hong Kong afterwards, the weather of Hong Kong was dominated by the northeast monsoon gradually and local winds remained strong. All tropical cyclone warning signals were cancelled at 3:40 p.m. on 18 October. The Strong Monsoon Signal was issued at the same time and lasted till 8:40 a.m. the next day.

Under the influence of Nesat, a maximum sea level (above chart datum) of 2.84 m was recorded at Quarry Bay and a maximum storm surge (above astronomical tide) of 0.76 m was recorded at Tai Miu Wan. At the Observatory Headquarters, the lowest instantaneous mean sea-level pressure of 1007.2 hPa was recorded at 2:38 p.m. on 17 October.

It was mainly cloudy and warm in Hong Kong on 17 October. With the strengthening of the northeast monsoon over southern China, local temperatures started to drop appreciably on the early morning of 18 October and the weather became cool in the afternoon, with temperatures generally about ten degrees lower than those of the day before. Affected by the outer rainbands of Nesat, there were occasional rain in Hong Kong on 18 October. More than 20 millimetres of rainfall were generally recorded over the southern part of Hong Kong.

There were at least 10 reports of fallen trees in Hong Kong during the passage of Nesat. Seven passengers were injured when a bus travelling on the Peak was hit by a fallen tree. Tram service was also disrupted due to a fallen tree in Central. A pedestrian was hurt by a fallen wall signboard in Tsim Sha Tsui.