Tropical Cyclones in 2020 > Review of tropical cyclones in 2020

2.1 Review of tropical cyclones in 2020

2.1.1 Tropical cyclones over the western North Pacific (including the South China Sea)

In 2020, a total of 25 tropical cyclones occurred over the western North Pacific (WNP) and the South China Sea (SCS) bounded by the Equator, 45°N, 100°E and 180°, less than the long-term (1961 - 2010) average figure of around 30. During the year, 12 of the tropical cyclones attained typhoon intensity or above, less than the long-term average (1961 - 2010) of about 15, with three of them reaching super typhoon intensity (maximum 10-minute wind speed of 185 km/h or above near the centre).

Figure 2.1 shows the monthly frequencies of the occurrence of tropical cyclones in WNP and SCS in 2020.

During the year, six tropical cyclones made landfall over China, with two of them crossing the south China coast within 300 km of Hong Kong. Four tropical cyclones made landfall over the Korean Peninsula, six traversed the Philippines and seven made landfall over Vietnam. With an estimated maximum sustained wind speed of 275 km/h and a minimum sea-level pressure of 895 hPa near the centre (Table 4.1), Super Typhoon Goni (2019) in October (Figure 2.3) is the most intense tropical cyclone over the WNP and the SCS in 2020. It is also the most intense tropical cyclone in the region since Super Typhoon Haiyan in November 2013.

2.1.2 Tropical cyclones in Hong Kong's area of responsibility

Amongst the 25 tropical cyclones in 2020, 18 of them occurred inside Hong Kong’s area of responsibility (i.e. the area bounded by 10°N, 30°N, 105°E and 125°E), more than the long-term annual average (1961-2010) figure of around 16 (Table 2.1). Ten of them developed within Hong Kong’s area of responsibility. Altogether, 405 tropical cyclone warnings to ships and vessels were issued by the Hong Kong Observatory this year (Table 4.2).

2.1.3 Tropical cyclones over the South China Sea

14 tropical cyclones affected SCS bounded by 10°N, 25°N, 105°E and 120°E in 2020, more than the long-term annual average (1961-2010) of around 12. Eight of them formed within SCS.

2.1.4 Tropical cyclones affecting Hong Kong

In 2020, the typhoon season in Hong Kong started on 12 June when Tropical Depression Nuri (2002) formed over the Philippines and entered the SCS, necessitating the issuance of the Standby Signal No. 1. The typhoon season ended with the cancellation of all tropical cyclone warning signals on 24 October when Severe Tropical Storm Saudel (2017) moved away from Hong Kong and weakened that day.  

  Five tropical cyclones affected Hong Kong during 2020 (Figure 2.2), slightly less than the long-term (1961-2010) average of about six in a year (Table 2.2). They were Tropical Storm Nuri (2002) in June, Tropical Storm Sinlaku (2003) in July to August, Typhoon Higos (2007) in August, Tropical Storm Nangka (2016) and Typhoon Saudel (2017) in October. The No. 9 Increasing Gale or Storm Signal was issued by the Hong Kong Observatory during the passage of Higos on 19 August. It was the highest tropical cyclone warning signal issued in 2020 and for the first time since Super Typhoon Mangkhut hitting Hong Kong in 2018. The No. 8 Gale or Storm Signal was issued during the passage of Nangka. The rest of the three tropical cyclones all necessitated the issuance of the Strong Wind Signal No. 3 in Hong Kong.

2.1.5 Tropical cyclone rainfall

Tropical cyclone rainfall (total rainfall recorded at the Hong Kong Observatory Headquarters from the time when a tropical cyclone comes within 600 km of Hong Kong to 72 hours after it has dissipated or moved more than 600 km away from Hong Kong) in 2020 was 421.7 mm (Table 4.8.1). This accounted for approximately 17.6 % of the year’s total rainfall of 2395.0 mm and was about 42.1 % below the 1961-2010 long-term average of 728.8 mm.

Typhoon Higos (2007) brought 172.2 mm of rainfall to the Hong Kong Observatory Headquarters (Table 4.8.1) and was the wettest tropical cyclone in 2020.

2.2 Monthly overview

A monthly overview of tropical cyclones in 2020 is given in this section. Detailed reports on tropical cyclones affecting Hong Kong, including reports of damage, are presented in Section 3.

No tropical cyclone formed over the western North Pacific and the South China Sea from January to April 2020.

Vongfong (2001) formed as a tropical depression over the western North Pacific about 1210 km east-southeast of Manila in the small hours on 11 May. It moved north-northwestwards slowly at first. Vongfong intensified into a tropical storm on the night of 12 May. It started to intensify rapidly and turned to move westwards the next day. Vongfong developed into a severe typhoon in the small hours on 14 May and reached its peak intensity in the morning with an estimated sustained wind of 165 km/h near its centre. It moved northwestwards across the Philippines and weakened gradually in the following two days. Vongfong finally degenerated into an area of low pressure over the Luzon Strait on the night of 16 May.

According to press reports, Vongfong brought at least one death and 100 injuries and damaged more than 10000 houses during its passage to the Philippines.

Nuri (2002) formed as a tropical depression over the Philippines about 110 km north-northwest of Manila in the small hours on 12 June and intensified gradually. It moved generally northwestward across the South China Sea during the day. Nuri developed into a tropical storm in the small hours on 13 June and reached its peak intensity with an estimated sustained wind of 75 km/h near its centre in the afternoon. Nuri made landfall over Yangjiang of Guangdong later in the morning of 14 June and weakened into an area of low pressure over inland Guangdong in the afternoon.

A tropical depression formed over the western North Pacific about 550 km east-northeast of Manila in the small hours on 13 July with an estimated sustained wind of 45 km/h near its centre. It generally tracked northwestwards and weakened into an area of low pressure over the Luzon Strait in the small hours of the next day.

A monsoon depression entered the South China Sea on 30 July and developed into a tropical depression the next night. The tropical depression generally tracked west-northwestward towards Hainan Island and was named Sinlaku (2003) on the afternoon of 1 August. Sinlaku intensified into a tropical storm over Beibu Wan in the small hours of the next day and reached its peak intensity with an estimated maximum sustained wind of 65 km/h. It made landfall over the northern part of Vietnam on the morning of 2 August and weakened into an area of low pressure over inland Vietnam that night.

Tropical depression Hagupit (2004) formed over the western North Pacific about 670 km south of Okinawa on the morning of 1 August. It moved generally northwestward across the seas east of Taiwan and intensified gradually. Hagupit developed into a typhoon on the afternoon of 3 August and reached its peak intensity at night with an estimated maximum sustained wind of 140 km/h near its centre. Hagupit made landfall over the coast of Zhejiang in the early morning of 4 August and weakened. It then turned to move northward across the vicinity of Zhejiang and Jiangsu and then tracked northeastward entered the Yellow Sea the next day. Hagupit finally evolved into an extratropical cyclone over the Yellow Sea at night.

According to press reports, Hagupit left at least one death and one injury when it skirted past the vicinity of Taiwan. Hagupit also brought heavy rain and squalls to Zhejiang and Jiangsu and there were severe flooding in many places. At least two persons were killed in Zhejiang and power supply to over 1.8 million households was suspended.

Jangmi (2005) formed as a tropical depression over the western North Pacific about 600 km south-southwest of Okinawa in the small hours on 9 August. It intensified into a tropical storm in the morning and rapidly moved northward across the vicinity of Ryukyu Islands. Jangmi reached its peak intensity on 10 August with an estimated maximum sustained wind of 85 km/h near its centre. It tracked north-northeast across the southeastern part of the Korean Peninsula during the day and evolved into an extratropical cyclone over the seas north of Honshu in the early morning of the next day.  

Mekkhala (2006) formed as a tropical depression over the northeastern part of the South China Sea about 470 km south-southeast of Dongsha on the night of 9 August and moved northwards. It intensified into a tropical storm the next morning. Mekkhala rapidly intensified at night and developed into a typhoon on the morning of 11 August. It reached its peak intensity before making landfall over Fujian with an estimated maximum sustained wind of 130 km/h near its centre. Mekkhala moved inland Fujian and dissipated gradually during the day.

According to press reports, many trees were fallen in Fujian during the passage of Mekkhala. Power supply to more than 160 000 households was suspended.

A tropical depression was formed over the western North Pacific about 320 km east-northeast of Iwo Jima on the night of 10 August with an estimated sustained wind of 45 km/h near its centre. It moved generally westward towards the vicinity of Ryukyu Islands. The tropical depression degenerated into an area of low pressure near Ryukyu Islands on the morning of 12 August.

Higos (2007) formed as a tropical depression over the northeastern part of the South China Sea at about 650 km east-southeast of Hong Kong on the night of 17 August. It generally moved northwestwards across the northern part of the South China Sea. While edging towards the vicinity of the Pearl River Estuary, Higos intensified rapidly the next day and developed into a severe tropical storm in the afternoon. Higos further intensified into a typhoon near the Pearl River Estuary that night, reaching its peak intensity in the small hours of 19 August with an estimated maximum sustained wind of 130 km/h near its centre. It made landfall over Zhuhai on the morning of 19 August. Higos then moved into the western part of Guangdong and weakened gradually during the day. It degenerated into an area of low pressure over Guangxi that night.

According to press reports, 15 persons were injured in Macao during the passage of Higos. There were flooding in low lying areas in Inner Harbour.

Bavi (2008) formed as a tropical depression over the western North Pacific about 350 km south-southeast of Taibei on the night of 21 August. It drifted generally northeastwards at first and intensified gradually. Bavi slowed down and developed into a typhoon on 24 August. It further intensified into a severe typhoon the next day and reached its peak intensity with an estimated maximum sustained wind of 165 km/h near its centre. Bavi then picked up speed to move northwards across the East China Sea and the Yellow Sea. It made landfall near vicinity of the northwestern part of the Korean Peninsula on the morning of 27 August. Bavi evolved into an extratropical cyclone over the northeastern part of China that night.

According to press reports, Bavi left at least one death to DPR Korea during its passage. There were fallen trees and electric poles in many places. Some of the roads were flooded.

Maysak (2009) formed as a tropical depression over the western North Pacific about 1100 km east-northeast of Manila on the morning of 28 August. It lingered around the sea areas east of the Philippines and intensified in the following two days. Maysak developed into a typhoon in the small hours of 30 August and accelerated northward. It further intensified into a super typhoon on the night of 31 August and tracked north-northwestward towards the vicinity of Ryukyu Islands. Maysak reached its peak intensity on the morning of 1 September with an estimated sustained wind of 195 km/h near its centre. Maysak then turned to move north-northeastward and swept across the East China Sea and the Korean Peninsula. It finally evolved into an extratropical cyclone on the afternoon of 3 September over the seas northeast of the Korean Peninsula.

According to press reports, at least 26 people were injured in Japan during the passage of Maysak. A cargo ship sank near Amami Oshima of the Kagoshima Prefecture with at least 42 people on board missing. Besides, at least two persons were killed and 12 people were injured when Maysak moved across the Korean Peninsula.

Haishen (2010) formed as a tropical depression over the western North Pacific about 510 km southeast of Iwo Jima on the morning of 1 September. It moved southwestward and intensified gradually on that day. Haishen turned to track west-northwestward across the western North Pacific on 2 September and developed into a typhoon in the small hours on 3 September. Haishen further intensified into a super typhoon on 4 September and reached its peak intensity with an estimated maximum sustained wind of 220 km/h near its centre. Turning to track north-northwestward gradually, Haishen swept across the seas west of Kyushu and then the Korean Peninsula and weakened gradually. Haishen finally evolved into an extratropical cyclone over the northeastern part of China in the small hours on 8 September.

According to press reports, Haishen left at least two deaths, four missing and 100 injuries in Japan during its passage. Haishen was the second storm hitting the Korean Peninsula within a week after Maysak, causing at least two deaths and wide-spread flooding. Many houses were damaged.

Noul (2011) formed as a tropical depression over the southern part of the South China Sea about 900 km east-southeast of Xisha on the night of 15 September. It moved west-northwestward and intensified gradually. Noul developed into a tropical storm on the morning of 16 September. It reached its peak intensity that night with an estimated maximum sustained wind of 85 km/h near its centre. Noul moved across the central part of Vietnam on 18 September and weakened. It finally degenerated into an area of low pressure over the Indochina Peninsula at night.

According to press reports, at least six people were killed in Vietnam during the passage of Noul.

Dolphin (2012) formed as a tropical depression over the western North Pacific about 1190 km south of Osaka on the night of 20 September. It tracked north-northeastward slowly and intensified gradually. Dolphin developed into a severe tropical storm on the afternoon of 22 September and reached its peak intensity that night with an estimated maximum sustained wind of 105 km/h near its centre. Dolphin then turned to move east-northeastward and finally evolved into an extratropical cyclone over the seas east of Japan on 24 September.

Kujira (2013) formed over the western North Pacific about 2040 km east-southeast of Iwo Jima on the night of 26 September. It moved generally northwestward and intensified gradually. Kujira intensified into a severe tropical storm on the night of 28 September and reached its peak intensity in the next morning with an estimated maximum sustained wind of 110 km/h near its centre. Kujira then gradually turned to track northeastward and finally evolved into an extratropical cyclone over the western North Pacific east of Japan on 30 September.

Chan-hom (2014) formed as a tropical depression over the western North Pacific about 350 km southwest of Iwo Jima in the small hours on 5 October and drifted northwards at first. Chan-hom turned to move west-northwestwards across the sea areas south of Japan the next day and intensified gradually. Chan-hom developed into a typhoon on the afternoon of 7 October and reached its peak intensity at night with an estimated maximum sustained wind of 130 km/h near its centre. Chan-hom turned gradually to move eastwards and weakened in the following few days. It finally degenerated into an area of low pressure over the western North Pacific to the north of Iwo Jima in the small hours on 12 October.

Linfa (2015) formed as a tropical depression over the southern part of the South China Sea about 670 km east-southeast of Da Nang on the morning of 10 October. It moved westwards towards the central part of Vietnam and intensified gradually. Linfa developed into a tropical storm in the small hours on 11 October, reaching its peak intensity in the morning with an estimated sustained wind of 75 km/h near its centre. Linfa made landfall over the central part of Vietnam in the afternoon and degenerated into an area of low pressure over Indo-China the next day.

According to press reports, Linfa brought torrential rain to Vietnam, leading to at least 17 deaths and 13 missing.

Nangka (2016) formed as a tropical depression over the central part of the South China Sea about 500 km southeast of Dongsha on the afternoon of 11 October. It then moved west-northwestwards towards Hainan Island and intensified gradually. Nangka intensified into a tropical storm on the afternoon of 12 October, reaching its peak intensity at night with an estimated maximum sustained wind of 85 km/h near its centre. It moved across Hainan Island on the night of 13 October and weakened gradually. Nangka entered Beibu Wan the next day and finally degenerated into an area of low pressure over inland Vietnam that night.

According to press reports, a cargo ship overturned near Qiongzhou Strait when Nangka was striking Hainan. Two crew members on board died and three were missing. Nangka also brought heavy rain and squalls to Vietnam, leaving at least two deaths and one missing.

Saudel (2017) formed as a tropical depression over the western North Pacific about 920 km east of Manila on the morning of 19 October. Saudel moved generally west-northwestwards and intensified gradually. It moved across Luzon on the night of 20 October and entered the central part of the South China Sea in the next morning. Saudel turned to move northwestwards during the day. It intensified into a typhoon on 22 October and reached its peak intensity the next day with an estimated sustained wind of 140 km/h near its centre. Affected by the dry northeast monsoon, Saudel then turned to track westwards and weakened gradually. It finally degenerated into an area of low pressure over the seas east of central Vietnam on the night of 25 October.

According to press reports, over 6000 people were evacuated because of flooding and landslips in the Philippines during the passage of Saudel.  

Molave (2018) formed as a tropical depression over the western North Pacific about 1100km east of Manila on the morning of 24 October. It moved generally westwards and intensified rapidly. Molave intensified into a typhoon on the night of 25 October and then moved across the central part of the Philippines. It entered the southern part of the South China Sea in the next morning. Molave further developed into a severe typhoon on 27 October, reaching its peak intensity with an estimated sustained wind of 165 km/h near its centre. Molave then weakened gradually and made landfall over the central part of Vietnam around noon on 28 October. Molave finally degenerated into an area of low pressure over Indo-China on 29 October.

According to press report, Molave brought torrential rain and squalls to the Philippines, leaving at least 9 deaths, 6 injuries and 2 missing. At least 27 people were killed and 74 were missing in Vietnam during the passage of Molave.

Goni (2019) formed as a tropical depression over the western North Pacific about 2100 km east of Manila on the morning of 28 October. It moved west to west-southwestwards and intensified rapidly. Goni intensified into a super typhoon on the morning of 30 October and reached its peak intensity in the small hours on 1 November with an estimated maximum sustained wind of 275 km/h near its centre. Goni is the most intense tropical cyclone in the region since Super Typhoon Haiyan in November 2013. It moved across the central part of the Philippines and weakened that night. Goni traversed the central part of the South China Sea in the following couple of days and degenerated into an area of low pressure over the seas east of Vietnam on 5 November.

According to press reports, the Philippines was directly hit by Super Typhoon Goni. At least 25 people were killed and over 170 000 houses were damaged.

Atsani (2020) formed as a tropical depression over the western North Pacific about 350 km south-southwest of Guam on the afternoon of 30 October. It moved generally northwestwards in the following two days. It moved towards the seas east of the Philippines and intensified gradually. Atsani intensified into a tropical storm in the small hours on 2 November. Atsani began to slow down in the small hours the next day and lingered over the seas northeast of the Philippines. Atsani intensified into a severe tropical storm on 4 November and reached its peak intensity the next day with an estimated maximum sustained wind of 105 km/h near its centre. It then picked up its speed to move west-northwestwards towards the coastal waters of southern part of Taiwan. Atsani entered the northeastern part of the South China Sea on 7 November and weakened rapidly. It finally degenerated into an area of low pressure over Taiwan Strait at night.

Etau (2021) formed as a tropical depression over the southern part of the South China Sea about 410 km northeast of Nansha on the night of 8 November and moved westwards. It intensified into a tropical storm on 9 November and reached its peak intensity that night with an estimated maximum sustained wind of 75 km/h near its centre. Etau made landfall over the southern part of Vietnam on 10 November and weakened rapidly. It degenerated into an area of low pressure over Indo-China that night.    

Vamco (2022) formed as a tropical depression over the western North Pacific about 1130 km east-southeast of Manila on the afternoon of 9 November. It moved west-northwestwards and intensified rapidly. Vamco developed into a typhoon on the morning of 11 November and moved across Luzon. It entered the central part of the South China Sea the next morning. It tracked westwards and intensified into a severe typhoon on 14 November, reaching its peak intensity with an estimated maximum sustained wind of 175 km/h near its centre. Vamco then weakened rapidly and made landfall over the central part of Vietnam the next afternoon. It finally degenerated into an area of low pressure over Indo-China that night.

According to press reports, Vamco left at least 101 deaths, 85 injuries and 10 missing in the Philippines during its passage. In Vietnam, at least one people was killed and 5 others were injured during the passage of Vamco.

Krovanh (2023) formed as a tropical depression over the southern part of the South China Sea about 350 km east of Nansha in the small hours on 20 December. It moved west to west-southwestwards and intensified gradually. Krovanh reached its peak intensity with an estimated maximum sustained wind of 55 km/h near its centre on the night of 20 December. Krovanh then continued to track southwestwards towards the seas south of Vietnam and weaken gradually. Krovanh finally degenerated into an area of low pressure over the seas south of Vietnam on 22 December.

Note: Casualties and damage figures were compiled from press reports.