TROPICAL CYCLONES IN 2009
2.1 Review of tropical cyclones in 2009
| 2.1.1 | Tropical cyclones over the western North Pacific (including the South China Sea) |
In 2009, a total of 30 tropical cyclones affected the western North Pacific and the South China Sea (i.e. the area bounded by the Equator, 45°N, 100°E and 180°, close to the 30-year (1971-2000) average of 29.6. During the year, 13 tropical cyclones attained typhoon intensity or above, about two below the normal figure. Five of them, namely Choi-Wan (0914), Parma (0917), Melor (0918), Lupit (0920) and Nida (0922) attained super typhoon intensity (maximum 10-minute wind speed of 185 km/h or above near the centre) over the western North Pacific.
The first tropical cyclone of the year formed in May and the last one in November. Figure 2.1 shows the monthly frequencies of the occurrence of tropical cyclones in the western North Pacific and the South China Sea in 2009.
During the year, eleven tropical cyclones hit Mainland China, two crossed over Taiwan, four affected Japan, six traversed or passed close to the Philippines and five made landfall over Vietnam.
The most intense tropical cyclones in 2009 were super typhoons Choi-Wan (0914) and Nida (0922). Both super typhoons had a maximum sustained wind speed of about 210 km/h and a minimum sea-level pressure of about 910 hPa (Table 4.1) when they were located over the western North Pacific about 520 km north of Guam (Fig. 2.3) and 370 km west of Guam respectively (Fig. 2.4).
Super Typhoon Parma (0917), which formed over the western North Pacific in late September, persisted for almost 16 days and was the tropical cyclone with the longest life span in the region since Typhoon Verne in 1994. Verne persisted for about 16 days.
The tracks of Severe Tropical Storm Goni (0907) and Super Typhoon Parma (0917) were the most peculiar in 2009. Under the influence of another tropical cyclone Morakot (0908) over the western North Pacific, Goni moved southwestwards skirting the western part of Hainan Island after making landfall over the western part of Guangdong (Fig. 2.5). It then turned to move eastwards to cross the South China Sea before dissipation. The track of Parma was affected by Super Typhoon Melor (0918) over the western North Pacific (Fig. 2.6). It lingered near northern Luzon for four days before moving west-northwestwards across the northern part of the South China Sea.
2.1.2 Tropical cyclones in Hong Kong's area of responsibility
Amongst the 30 tropical cyclones in 2009, 17 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 30-year (1971-2000) annual average of 15.4 (Table 2.1). Nine of these 17 tropical cyclones developed within Hong Kong's area of responsibility. Altogether, 523 tropical cyclone warnings to ships and vessels were issued by the Hong Kong Observatory in 2009 (Table 4.2).
2.1.3 Tropical cyclones over the South China Sea
Thirteen tropical cyclones affected the South China Sea (i.e. the area bounded by 10°N, 25°N, 105°E and 120°E) in 2009. Five of them formed over the area. Eight moved into the area from the western North Pacific.
2.1.4 Tropical cyclones affecting Hong Kong
In 2009, the typhoon season in Hong Kong started on 20 June when Severe Tropical Storm Linfa (0903) moved towards the south China coast and and necessitated the issuance of the Standby Signal No.1. The typhoon season ended on 28 September as Typhoon Ketsana moved away.
Eight tropical cyclones affected Hong Kong (Figure 2.2), more than the average number of 6.5 (Table 2.2). These eight tropical cyclones were Severe Tropical Storm Linfa (0903) and Tropical Storm Nangka (0904) in June, Tropical Storm Soudelor (0905) and Typhoon Molave (0906) in July, Severe Tropical Storm Goni (0907) in August, Tropical Storm Mujigae (0913), Typhoon Koppu (0915) and Typhoon Ketsana (0916) in September. Three of them, Molave, Goni and Koppu necessitated the issuance of the No. 8 Gale or Storm Signal or higher signals in Hong Kong, also more than the normal of one to two per year. Typhoon Molave passed about 40 km to the north-northeast of the Hong Kong Observatory Headquarters and necessitated the issuance of the Increasing Gale or Storm Signal No. 9, the highest tropical cyclone warning signal in 2009. The Strong Wind Signal No. 3 was issued during the passages of Nangka, Soudelor and Mujigae while Linfa and Ketsana necessitated the issuance of the Standby Signal No. 1 in Hong Kong.
During the passage of Koppu, the combined effect of storm surge and high tide raised the sea level to a maximum of 3.43 metres at Tai Po Kau in the northeastern part of Hong Kong, one of the highest sea levels recorded in the past decade.
2.1.5 Tropical cyclone rainfall
Tropical cyclone rainfall (the total rainfall recorded at the Hong Kong Observatory from the time when a tropical cyclone is centred within 600 km of Hong Kong to 72 hours after it has dissipated or moved farther than 600 km away from Hong Kong) in 2009 was 822.4 mm (Table 4.8.1). This was 10% above the normal of 745.5 mm and accounted for some 38% of the year's total rainfall of 2182.3 mm.
Typhoon Koppu, which affected Hong Kong on 13-15 September, brought 273.0 mm of rainfall to the Hong Kong Observatory Headquarters, and was the wettest tropical cyclone in 2009.
A monthly overview of tropical cyclones is given in this section. Detailed reports on tropical cyclones affecting Hong Kong are presented in Section 3.
JANUARY TO APRIL
No tropical cyclone occurred over the western North Pacific and the South China Sea from January to April.
MAY
Kujira (0901) formed as a tropical depression over the western North Pacific about 390 km east-southeast of Manila on 2 May and moved generally northeastwards. It intensified into a tropical storm on the morning of 3 May and then a severe tropical storm that evening. According to press reports, rainbands associated with Kujira set off landslides and swamped farmlands in the northeastern Philippines, leaving at least 11 people dead and nine others missing. Kujira intensified further into a typhoon on 4 May and continued to move in a northeasterly direction across the western North Pacific. It weakened into a severe tropical storm on the morning of 7 May and then a tropical storm that afternoon. Kujira became an extra-tropical cyclone over the western North Pacific to the northeast of Ogasawara Islands that night.
Chan-hom (0902) formed as a tropical depression over the central part of the South China Sea about 320 km west-southwest of Nansha on 3 May. Moving slowly northeastwards, it intensified into a tropical storm that evening. Chan-hom moved northwards slowly on 4 May and intensified into a severe tropical storm the next day, but turned to move east-northeastwards on 6 May. Chan-hom intensified into a typhoon on 7 May and crossed northern Philippines that night. According to press reports, Chan-hom brought heavy rain to the northern Philippines. There were many incidents of collapsed houses and landslides. Over 25 people were killed and three others missing. Some 4 000 people were affected. Chan-hom moved eastwards into the western North Pacific on 8 May. It weakened into a severe tropical storm in the early hours of that day and then a tropical storm that afternoon. Chan-hom weakened further into a tropical depression on 9 May and moved generally north-northwestwards for the following three days. It weakened into an area of low pressure near the Rykuyu Islands on 12 May.
JUNE
Tropical Depression Linfa (0903) formed over the northern part of the South China Sea about 520 km south-southeast of Hong Kong on 17 June and moved slowly. It intensified into a tropical storm the next day. Linfa started to move northwards on 19 June and intensified into a severe tropical storm that night. Linfa moved north-northeastwards across the northeastern part of the South China Sea on 20 June. It weakened into a tropical storm in the afternoon of 21 June and made landfall in Fujian that evening. After moving northeastwards across the coast of Fujian on 22 June, Linfa entered the East China Sea and weakened into a tropical depression that evening. It further weakened into an area of low pressure over the East China Sea on 23 June.
Tropical Depression Nangka (0904) formed over the western North Pacific about 860 km east-southeast of Manila on 23 June. Moving west-northwestwards, it intensified into a tropical storm that afternoon. Nangka crossed the central Philippines the next day and entered the South China Sea in the evening. Nangka turned to move generally northwestwards across the South China Sea on 25 June. It moved generally north-northwestwards on 26 June approaching the coast of eastern Guangdong and weakened into a tropical depression that evening. Nangka made landfall over the coastal areas of Daya Bay in the small hours of 27 June. Nangka moved further inland and weakened into an area of low pressure over Guangdong that morning.
JULY
Tropical Depression Soudelor (0905) formed over the South China Sea about 700 km east-southeast of Hong Kong on 10 July and moved west-northwestwards across the northern part of the South China Sea. It intensified into a tropical storm on the afternoon of 11 July. Soudelor crossed the southern tip of the Leizhou Peninsula on the morning of 12 July and entered Beibu Wan that afternoon. It made landfall over the coast of northern Vietnam and weakened into a tropical depression that evening. Soudelor further weakened into an area of low pressure over northern Vietnam that night.
A tropical depression formed over the western North Pacific about 230 km east-southeast of Gaoxiong on the morning of 13 July and moved generally northwestwards. It made landfall over the coast of southeastern Taiwan and moved across southern Taiwan that afternoon. The tropical depression entered the Taiwan Strait that night. It made landfall over the coastal areas of Fujian and weakened into an area of low pressure on the morning of 14 July.
Tropical Depression Molave (0906) formed over the western North Pacific about 670 km east of Manila on 15 July and moved generally northwestwards. It intensified into a tropical storm the next day. While crossing the Luzon Strait on 17 July, Molave intensified into a severe tropical storm in the afternoon. It entered the South China Sea and turned to move west-northwestwards that night. Molave intensified into a typhoon on the morning of 18 July. On the early hours of 19 July, Molave made landfall over Dapeng Peninsula, Shenzhen and weakened into a severe tropical storm. It moved across western Guangdong and weakened into a tropical storm in the morning. Molave weakened into a tropical depression that afternoon and subsequently into an area of low pressure over Guangxi at night.
AUGUST
Goni (0907) developed into a tropical depression over the western North Pacific about 720 km east-northeast of Manila on 1 August. Tracking west-northwestwards, it crossed northern Luzon that night and entered the South China Sea the next morning. On 3 August, Goni slowed down and its track became erratic but generally moved towards the coast of Guangdong. Goni intensified into a tropical storm that evening and further into a severe tropical storm on 4 August. It made landfall over western Guangdong on 5 August and weakened into a tropical storm. Goni turned to move west or west-southwestwards across the coastal areas of western Guangdong and weakened into a tropical depression on 6 August. It then moved southwestwards to cross Leizhou Peninsula and entered Beibu Wan on the next day. It intensified into a tropical storm again on 8 August and turned to move eastwards that night. Goni crossed the northern part of the South China Sea on 9 August and weakened into an area of low pressure over the northern part of the South China Sea that afternoon.
Morakot (0908) formed as a tropical depression over the western North Pacific about 1 010 km east-southeast of Okinawa on 4 August. Moving west-northwestwards, it intensified into a tropical storm that day. Morakot intensified first into a severe tropical storm and further into a typhoon on 5 August, and turned to move westwards towards Taiwan on the following day. It slowed down on 7 August and crossed Taiwan on a northwesterly track the next day. Morakot crossed the Taiwan Strait on 9 August and made landfall near Xiapu, Fujian and weakened into a severe tropical storm. It weakened further into a tropical storm on 10 August and moved northwards across eastern China. Morakot turned to move north-northeastwards on the next day and weakened into a tropical depression. It became an extra-tropical cyclone over the Yellow Sea on 12 August. According to press reports, Morakot brought torrential rain to Taiwan, triggering floods and unlashing mudslides, and caused the most severe damage there in about 50 years. More than 460 people were killed, 190 missing and 40 people injured in Taiwan, of which hundreds were buried beneath the rubble in the village of Hsiaolin in southern Taiwan. The agricultural losses in Taiwan exceeded NT15.8 billion, with more than 18 000 hectares of farmland flooded. Moreover, at least six people were killed, three people missing and over 6 000 houses collapsed in Fujian, Zhejiang, Jiangxi and Anhui. The direct economic loss was estimated to be over 9 billion RMB.
Etau (0909) formed as a tropical depression over the western North Pacific about 260 km west-southwest of Iwo Jima on 8 August and moved northwestwards. It intensified into a tropical storm the next day. Etau turned to move generally northeastwards on 10 August. It moved eastwards on 11 August, skirting the coastal waters of southern Japan. According to press reports, Etau brought heavy rain to Japan causing floods and landslides, inundated a town, and disrupted air and rail links. At least 14 people were killed and 18 people injured. On 13 August, Etau weakened first into a tropical depression and subsequently became an extra-tropical cyclone over the western North Pacific to the east of Japan.
Having formed over the central part of the North Pacific, a tropical depression crossed the International Date Line and entered the western North Pacific on 13 August on a westward track. It turned to move northwestwards on 15 August, and turned further to the northeast the next day. The tropical depression took up a westerly track again and weakened into an area of low pressure over the western North Pacific to the east-southeast of Wake Island on 17 August.
Vamco (0910) formed as a tropical depression over the western North Pacific about 1 540 km east of Guam on 17 August and moved generally north-northwestwards. Vamco intensified first into a tropical storm and then a severe tropical storm on 18 August, and into a typhoon the next day. Vamco intensified further into a severe typhoon on 20 August, but weakened into a typhoon two days later. It turned to move northwards on 23 August and north-northeastwards the next day. Vamco weakened into a severe tropical storm on 25 August and became an extra-tropical cyclone over the western North Pacific to the east-northeast of Hokkaido, Japan the next day.
Krovanh (0911) formed as a tropical depression about 880 km east-southeast of Iwo Jima on 28 August and moved north-northwestwards. It intensified into a tropical storm that evening. Krovanh moved northwestwards the next day and intensified into a severe tropical storm on 30 August. It turned to move north-northeastwards skirting the eastern coast of Japan on 31 August. Krovanh weakened into a tropical storm on 1 September and became an extra-tropical cyclone to the east of Hokkaido that evening.
Having formed over the central part of the North Pacific, a tropical depression crossed the International Date Line and entered the western North Pacific on 30 August on a west-northwestward track. The tropical depression dissipated over the western North Pacific to the south-southeast of Wake Island on 1 September.
SEPTEMBER
Dujuan (0912) formed as a tropical depression over the western North Pacific about 940 km south-southeast of Okinawa on 3 September and moved slowly at first. It intensified into a tropical storm on 4 September and started to move generally northeastwards across the western North Pacific. Dujuan intensified into a severe tropical storm on 5 September and moved north-northeastwards. It moved east-northeastwards across the western North Pacific to the south of Japan on 8 September and weakened into a tropical storm. Dujuan became an extra-tropical cyclone over the western North Pacific to the east of Japan on 10 September.
Mujigae (0913) developed into a tropical depression over the central part of the South China Sea about 790 km southeast of Hong Kong on the morning of 9 September. It moved northwestwards at first but took on a west-northwesterly track across the northern part of the South China Sea that afternoon. Mujigae intensified into a tropical storm on 10 September over the northern part of the South China Sea to the south-southeast of Hong Kong and turned to move westwards at night. It moved across the northern part of Hainan Island and entered Beibu Wan on 11 September. It made landfall over northern Vietnam on the morning of 12 September and weakened into a tropical depression. Mujigae weakened further into an area of low pressure over northern Vietnam that afternoon.
Choi-Wan (0914) formed as a tropical depression over the western North Pacific about 940 km east of Guam on 12 September. It moved west-northwestwards and intensified gradually into a severe tropical storm the next day. On 14 September, Choi-Wan became a typhoon over the Pacific about 430 km east-northeast of Guam and a severe typhoon that evening. It continued to intensify further into super typhoon on 15 September. Choi-Wan weakened into a severe typhoon on 18 September as it turned to move north-northwestwards. It weakened into a typhoon to the west of Iwo Jima that evening. Choi-Wan turned to move northeast on 19 September. It weakened into a severe tropical storm on 20 September and became an extra-tropical cyclone to the east of Japan that evening.
Koppu (0915) developed into a tropical depression over the western North Pacific about 490 km northeast of Manila on 12 September. Moving west-northwestwards, it crossed the Luzon Strait that night. Koppu entered the northern part of the South China Sea on a westerly track on the morning of 13 September and intensified into a tropical storm that evening. Koppu became a severe tropical storm on the morning of 14 September and turned to move northwestwards. It intensified into a typhoon about 190 km south-southeast of Hong Kong that afternoon, and took up a west-northwesterly track at night. Koppu made landfall over western Guangdong on the morning of 15 September and weakened into a severe tropical storm. It weakened further into a tropical storm that afternoon. Koppu weakened into a tropical depression on the small hours of 16 September and dissipated over Guangxi thereafter.
Ketsana (0916) formed as a tropical depression over the western North Pacific about 810 km east of Manila on 25 September and moved westwards. Ketsana intensified into a tropical storm and moved across the Philippines on 26 September, entering the South China Sea that evening. Ketsana intensified into a severe tropical storm on 27 September and further into a typhoon over the central part of the South China Sea near Xisha the next day. Ketsana made landfall over the central part of Vietnam on 29 September and weakened into a severe tropical storm. It weakened first into a tropical storm and further into a tropical depression on 30 September. Ketsana dissipated near the border between Laos and Thailand that night.
Parma (0917) developed as a tropical depression over the western North Pacific about 260 km southeast of Yap on 29 September and moved westwards. It intensified into a tropical storm that evening. Moving west-northwestwards, Parma intensified first into a severe tropical storm and became a typhoon over the Pacific about 300 km west of Yap on 30 September. Parma intensified into a severe typhoon on the morning of 1 October and further into a super typhoon that afternoon. It gradually weakened into a typhoon on 2 October and turned to move northwestwards. Parma crossed the northern part of Luzon on 3 October and lingered near northern Luzon in the following four days. Its slow and erratic movement during the period was due to another tropical cyclone, Melor, over the Pacific during that time. Parma weakened into a severe tropical storm on 5 October and gradually weakened into a tropical depression on 7 October. It resumed a westward movement across Luzon on 8 October and re-intensified into a tropical storm. Palma entered the South China Sea on 9 October and moved west to west-northwestwards across the northern part of the South China Sea for the following three days. Parma made landfall over the southeastern part of Hainan Island during the afternoon of 12 October, but intensified into a severe tropical storm over Beibu Wan on the following day. It weakened first into a tropical storm on 14 October, made landfall over northern Vietnam that afternoon and weakened further into a tropical depression. Parma dissipated over northern Vietnam during the early hours of 15 October. According to press reports, rainstorms associated with Parma triggering severe flooding and landslides in the Philippines where around 200 people were killed. In Hainan Island, around 540 000 hectares of crops were damaged and the direct economic losses amounted to 51.70 million RMB. Three fishing boats sank in the waters of Hainan Island and the South China Sea, killing four fishermen with eight others missing. A total of 62 fishing boats sank in the seas of Vietnam but no casualties were reported.
Melor (0918) formed as tropical depression over the western North Pacific about 1 660 km east-southeast of Guam on 29 September and moved west-northwestwards. It became a tropical storm on 30 September. Melor gradually intensified into a typhoon about 910 km east of Guam on 1 October. It intensified into a severe typhoon on 2 October and became a super typhoon two days later. Melor turned to move northwestwards over the Pacific to the southeast of Okinawa on 6 October. It turned to move north-northeastwards over the Pacific to the south of Kyushu, Japan on 7 October and weakened into a severe typhoon. Melor weakened further into a typhoon on 8 October and made landfall over the southern part of Honshu around daybreak. It further weakened into a severe tropical storm and moved across the eastern part of Honshu that afternoon. Melor became an extra-tropical cyclone over the Pacific to the east of Honshu that evening . In the fury of Melor, four people were killed and more than 100 injured in Japan.
OCTOBER
Nepartak (0919) formed as a tropical depression over the western North Pacific about 390 km north-northwest of Guam on 8 October and moved north-northwestwards. It intensified into a tropical storm the next day. Nepartak slowed down on 10 October and turned to move northeastwards on 11 October, passing to the southeast of Iwo Jima. It speeded up towards the northeast on 12 October and became an extra-tropical cyclone over the Pacific to the east of Japan on 14 October.
Lupit (0920) formed as a tropical depression over the western North Pacific about 320 km southeast of Guam on 15 October and moved west-northwestwards, intensifying into a tropical storm that evening. It intensified into a severe tropical storm on 16 October. Lupit slowed down and turned to move northwards on 17 October. It intensified into a typhoon over the Pacific to the northwest of Yap that day and further into a severe typhoon that evening. Lupit moved slowly northeastwards and became a super typhoon on 18 October. It resumed a mainly westerly track on 19 October, and weakened gradually into a typhoon in the following two days. Lupit became slow moving again over the waters to the northeast of Luzon on 22 October, but turned to move north-northeastwards and weakened into a severe tropical storm on 23 October. It weakened further into a tropical storm on 25 October over the Pacific to the southeast of Okinawa. Lupit moved across the seas to the southeast of Japan on 26 October. It became an extra-tropical cyclone over the Pacific to the east of Japan on 27 October.
A tropical depression formed over the South China Sea about 250 km east-northeast of Da Nang on 19 October and moved slowly northwards. The tropical depression turned to move west-northwestwards and dissipated over the waters south of Hainan the following day.
Mirinae (0921) formed as a tropical depression over the western North Pacific about 400 km east of Guam on 26 October and moved west-northwestwards. It intensified into a tropical storm the next day and gradually into a typhoon over the Pacific to the east of Manila on 28 October and turned to move westwards. Mirinae crossed Luzon and weakened into a severe tropical storm during the small hours of 31 October, and subsequently entered the central part of the South China Sea during the morning. During the passage of Mirinae, at least 20 people were killed and four others injured in the Philippines. Electricity supply to parts of Manila was disrupted. Mirinae weakened into a tropical storm over the central part of the South China Sea on the morning of 1 November. It made landfall over the central part of Vietnam on the evening of 2 November and dissipated over southern Vietnam the following morning. According to press reports, Mirinae triggered severe flooding in central Vietnam where at least 90 people were killed and 22 others missing. More than 13 000 houses were damaged and some 5 000 hectares of farmland were affected.
NOVEMBER
A tropical depression formed over the western North Pacific about 580 km east-northeast of Manila on 2 November and moved westwards. The tropical depression turned to move southwestwards and dissipated over the waters to the east of Luzon the following morning.
Another tropical depression formed over the western North Pacific about 1 180 km west of Wake Island on 7 November and moved generally eastwards. It dissipated over the western North Pacific on 10 November.
Nida (0922) formed as a tropical depression over the western North Pacific about 820 km south-southeast of Guam on 22 November and was slow-moving initially. Nida intensified into a tropical storm on 23 November and moved generally northwestwards. It intensified into a severe tropical storm the next day. Nida intensified into a typhoon about 350 km south-southwest of Guam on the morning of 25 November. It continued to strengthen further during the day and became a super typhoon that evening. Nida became slow-moving again on 28 and 29 November to the south-southwest of Iwo Jima. It weakened into a severe typhoon on 29 November and a typhoon on 30 November and moved west-northwestwards. Nida weakened gradually into a tropical storm on 2 December and further into a tropical depression on 3 December. It dissipated over the western North Pacific about 770 km west-southwest of Iwo Jima that evening.
A tropical depression formed over the western North Pacific about 870 km southeast of Manila on 24 November and moved slowly. The tropical depression dissipated over the waters on 25 November.
Another tropical depression formed over the southern part of the South China Sea about 570 km south-southeast of Ho Chi Minh City on 24 November and moved generally east-northeastwards. The tropical depression dissipated over the southern part of the South China Sea on 26 November.
DECEMBER
No tropical cyclone formed over the western North Pacific and the South China Sea in December.
Note: Casualties and damage figures were compiled from press reports.
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