Report on Typhoon Chaba (2203)

Typhoon Chaba (2203)
29 June - 3 July 2022

Chaba was the first tropical cyclone affecting Hong Kong in 2022. The No. 8 Gale or Storm Signal was issued during the passage of Chaba and it is also the first time on the HKSAR Establishment Day.

Chaba developed into a tropical depression over the central part of the South China Sea about 460 km east-southeast of Xisha on the morning of 29 June. It moved slowly west-northwestwards on that day and intensified gradually. Chaba developed into a tropical storm the next day and moved generally north-northwestwards towards the coast of western Guangdong. It further intensified into a typhoon on the morning of 2 July, reaching its peak intensity with an estimated wind of 120 km/h near its centre. Chaba made landfall near Maoming later in that afternoon. It then moved inland and weakened afterwards. Chaba finally degenerated into an area of low pressure over inland Guangxi on the night of 3 July.

According to press reports, Chaba brought torrential rain and squalls to Guangdong and there were flooding over many places. Power supply to over 230 000 households in Maoming was suspended. Chaba also triggered numerous of tornados in Guangdong, resulting in damage to a large number of buildings. Under inclement weather, a construction vessel sank over the seas about 160 miles southwest of Hong Kong. 12 crew members died and 14 others were reported missing.

The Standby Signal No. 1 was issued at 9:10 p.m. on 29 June when Chaba was about 760 km south-southeast of Hong Kong. Local winds were moderate to fresh easterlies, occasionally reaching strong force offshore and on high ground during the night. With Chaba edging closer to the coast of western Guangdong, the No. 3 Strong Wind Signal was issued at 10:40 p.m. on 30 June when Chaba was about 570 km south of the territory. Local winds were generally strong from the east during the day of 1 July, occasionally reaching gale force offshore and on high ground. As Chaba was expected to further intensify and its associated gale force winds would also continue to edge closer to the Pearl River Estuary, the No. 8 Southeast Gale or Storm Signal was issued at 7:10 p.m. on 1 July when Chaba was about 370 km south-southwest of Hong Kong. Local winds were strong to gale force east to southeasterlies, occasionally reaching storm force offshore and on high ground at night and the next morning.

Chaba came closest to Hong Kong at around 10 a.m. on 2 July when it skirted past about 310 km west-southwest of the territory. With Chaba making landfall near Maoming and gradually departing from Hong Kong, local winds moderated later in the afternoon and the No. 3 Strong Wind Signal was issued to replace the No. 8 Southeast Gale or Storm Signal at 4:20 p.m. on 2 July. As the outer rainband associated with Chaba kept affecting the Pearl River Estuary, strong south to southeasterly winds continued to affect Hong Kong on the night of 2 July and the morning of 3 July and occasionally reached gale force offshore and on high ground. Chaba continued to weaken and moved further away from Hong Kong on 3 July. The Standby Signal No. 1 was issued to replace the No. 3 Strong Wind Signal at 2:10 p.m. on that day. With Chaba degenerating into an area of low pressure over inland Guangxi, all tropical cyclone warning signals were cancelled at 7:40 p.m. on that night. However, under the influence of the southwest monsoon, strong winds still affected the offshore waters and high ground of Hong Kong and necessitated the issuance of the Strong Monsoon Signal from 7:50 p.m. on 3 July till 7:45 a.m. on 5 July.

Under the influence of Chaba, maximum hourly mean winds of 102, 83 and 64 km/h and maximum gusts of 149, 107 and 106 km/h were recorded at Ngong Ping, Cheung Chau and Green Island respectively. A maximum sea level (above chart datum) of 3.21 m was recorded at Tsim Bei Tsui and a maximum storm surge (above astronomical tide) of 0.70 m was recorded at Tai Po Kau and Shek Pik. The lowest instantaneous mean sea-level pressures recorded at some selected stations are as follows:

Affected by the outer rainbands of Chaba, there were occasional heavy squally showers and thunderstorms in Hong Kong from 30 June to 3 July. Over 150 mllimetres of rainfall were recorded over most parts of the territory during this period and rainfall even exceeded 250 millimetres in Causeway Bay and Wan Chai.

In Hong Kong, at least 3 persons were injured during the passage of Chaba. There were 595 reports of fallen trees and two reports of flooding. The fallen trees in Tai Wai and Central damaged two taxis. Some scaffoldings at Central, Sham Shui Po and Sha Tin collapsed. An advertisement banner at Wong Tai Sin and a flower plaque at Ma Liu Shui were also blown down by strong winds. 35 flights to the Hong Kong International Airport were diverted.