Typhoon Kalmaegi

Typhoon Kalmaegi (1415)
12 to 17 September 2014

        Kalmaegi was the fourth tropical cyclone necessitating the issuance of tropical cyclone warning signal by the Hong Kong Observatory in 2014. It was also the first tropical cyclone requiring the issuance of Gale or Storm Wind Signal No. 8 in the year.

        Kalmaegi formed as a tropical depression over the western North Pacific about 1430 km east of Manila on the morning of 12 September. It moved west-northwestwards and intensified gradually into a typhoon. Kalmaegi moved across the northern part of Luzon on the night of 14 September and maintained a good pace after entering the South China Sea the next morning. It reached peak intensity with an estimated sustained wind of 140 km/h near its centre before making landfall near Wenchang over the northeastern part of Hainan Island on the morning of 16 September. After crossing Beibu Wan in the afternoon, Kalmaegi made landfall over the northern part of Vietnam that night. Moving inland and weakening gradually, it finally became an area of low pressure over Yunnan on the afternoon of 17 September.

        According to press reports, three people were killed and three others were missing after a passenger ferry sank over the seas off the central part of the Philippines during the passage of Kalmaegi. In China, Kalmaegi also wreaked havoc in Hainan Island, western Guangdong and Guangxi, resulting in at least three deaths, one missing and about 6 million people affected. Transportation services were suspended. Storm surge triggered by Kalmaegi caused backflow of sea water in coastal areas, resulting in severe flooding in some areas. Sea level at Haikou was the highest since record began in 1973. There was also backflow of sea water inside the harbour of Macao, causing flooding in many places. A cargo ship lost power at seas about 20 km southwest of Macao, 14 crewmen were rescued with one injured.

        As Kalmaegi was a fast-moving storm with an extensive circulation, the Standby Signal No. 1 was issued by the Hong Kong Observatory at 11:35 p.m. on 14 September when it was about 850 km southeast of the territory. It was the first time the Standby Signal No. 1 was issued for a tropical cyclone centred outside 800-km range of Hong Kong since Typhoon Gordon in 1989. Local winds were moderate to fresh from the northeast on the morning of 15 September. With Kalmaegi moving steadily towards the south China coast, the Strong Wind Signal No. 3 was issued at 12:40 p.m. when it was about 510 km south-southeast of Hong Kong. Local winds strengthened gradually in the afternoon, becoming fresh to strong east to northeasterlies and occasionally reaching gale force offshore and on high ground. As Kalmaegi continued to edge closer to the south China coast, the No. 8 Southeast Gale or Storm Signal was issued at 10:30 p.m. when Kalmaegi was about 370 km south of Hong Kong. East to southeasterly gales generally affected the territory overnight, with storm force winds offshore and winds even reaching hurricane force occasionally on high ground. Sustained gale force winds or above were attained at four out of the eight reference stations in the network of reference anemometers under the tropical cyclone warning system of Hong Kong.

        Kalmaegi was closest to the territory in the small hours of 16 September as it skirted past about 370 km to the south-southwest. Winds subsided gradually as Kalmaegi moved away from Hong Kong. The No. 8 Southeast Gale or Storm Signal was replaced by the Strong Wind Signal No. 3 at 10:40 a.m that morning. With Kalmaegi moving further away from the territory in the afternoon, the Standby Signal No. 1 was issued at 8:40 p.m. As Kalmaegi moved further inland into the northern part of Vietnam, all tropical cyclone warning signals were cancelled at 2:10 a.m. Nevertheless, strong winds still affected the offshore waters of Hong Kong under the combined effect of the outer circulation of Kalmaegi and a ridge of high pressure along the southeastern coast of China. The Strong Monsoon Signal was issued immediately afterwards and lasted till 6:15 p.m. that day.

        Under the influence of Kalmaegi, a maximum hourly mean wind of 96 km/h was recorded at Cheung Chau Beach, while maximum gusts of 175 km/h were recorded at Ngong Ping. A maximum sea level (above chart datum) of 3.28 m and a maximum storm surge (above astronomical tide) of 1.20 m were 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	998.7	16/9	12:36 a.m.
Cheung Chau	997.6	16/9	03:47 a.m.
Hong Kong International Airport	998.0	16/9	03:59 a.m.
King’s Park	998.3	16/9	12:38 a.m.
Lau Fau Shan	998.7	16/9	12:53 a.m.
Waglan Island	997.5	16/9	03:45 a.m.

        Local weather was very hot with sunny periods at first on 15 September. Under the influence of the outer circulation of Kalmaegi, the weather became cloudy to overcast with squally showers and a few thunderstorms in the latter part of the day. The outer rainbands of Kalmaegi continued to bring heavy squally showers and a few thunderstorms to the territory on 16 September. More than 50 millimetres of rainfall were recorded over most parts of the territory during these two days, with rainfall over the northern part of the New Territories and the western part of Hong Kong Island exceeding 100 millimetres.

        In Hong Kong, at least 29 people were injured during the passage of Kalmaegi. There were 1352 reports of fallen trees, five reports of flooding, one report of landslide and many incidents of blown down objects. A scaffolding at Ta Chuen Ping Street of Kwai Chung collapsed, damaging a lorry and a minibus. A tree at Fuk Loi Estate in Tsuen Wan fell down, with some of the branches smashing through the glass windows of a residential flat. Storm surge triggered by Kalmaegi caused backflow of sea water in some low lying areas. Village houses near the coast at Lei Yue Mun became flooded and many residents had to be evacuated. The pavement at the South Waterfront Promenade at Tseung Kwan O was also damaged by sea waves. About 300 hectares of farmland in the New Territories were affected. At the Hong Kong International Airport, 131 flights were cancelled, 1 234 delayed and 20 aircraft were diverted.