TROPICAL CYCLONES IN 2007
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2.1 Review of tropical cyclones in 2007
In 2007, 25 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°). In the past 10 years (1998-2007), with the exception of 2004, the annual number of tropical cyclones in this ocean basin has been less than the 30-year (1961-1990) average of 31. Throughout the year, 13 tropical cyclones attained typhoon strength, three less than the normal figure. Only five tropical cyclones occurred in the western North Pacific and South China Sea from January to July, about half of the mean total number of tropical cyclones for the same period in 1961-1990. The rest of the 20 tropical cyclones formed between August and November. The first tropical cyclone of the year formed in March. The monthly frequencies of the occurrence of tropical cyclones in the western North Pacific and the South China Sea in 2007 are shown in Figure 2.1. During the year, eight tropical cyclones hit mainland China, five affected Taiwan, five affected Japan (including Ryukyu Islands), one made landfall over Republic Of Korea, four traversed the Philippines, another two made landfall over Vietnam. The most intense tropical cyclone in 2007 was Sepat (0708). Sepat had an estimated maximum wind speed of about 205 km/h and a minimum sea-level pressure of about 920 hPa when it was located over the western North Pacific to the southeast of Taiwan. Pabuk (0706) was the tropical cyclone with the most peculiar track in 2007. In Hong Kong, the Hong Kong Observatory had to re-issue the tropical cyclone warning signals for Pabuk on 10 August after all signals had been cancelled on 9 August. 2.1.2 Tropical cyclones in Hong Kong's area of responsibility Amongst those 25 tropical cyclones in 2007, 12 occurred inside Hong Kong's area of responsibility (i.e. the area bounded by 10°N, 30°N, 105°E and 125°E), less than the 30-year (1961-1990) annual average of 16.4 (Table 2.1). Five of these 12 tropical cyclones developed within Hong Kong's area of responsibility. Altogether, 351 tropical cyclone warnings to ships and vessels were issued by the Hong Kong Observatory in 2007 (Table 4.2). 2.1.3 Tropical cyclones over the South China Sea There were 8 tropical cyclones affecting the South China Sea (i.e. the area bounded by 10°N, 25°N, 105°E and 120°E) in 2007. Three of them formed over the area. Five moved into the area from the western North Pacific. 2.1.4 Tropical cyclones affecting Hong Kong Two tropical cyclones, namely Severe Tropical Storm Pabuk (0706) and Tropical Storm Francisco (0713), affected Hong Kong in 2007 (Figure 2.2), much less than the normal number of 6 to 7. The fewer number of tropical cyclones affecting Hong Kong were mainly due to the stronger-than-normal sub-tropical ridge of high pressure over the western North Pacific and the South China Sea in July, September and October, thus suppressing the convection over the areas. Pabuk, which affected Hong Kong in August, necessitated the issuance of the first Number 8 Gale or Storm Signal since the passage of Tropical Storm Kompasu in 2004, and was also the highest signal issued in 2007. Francisco in September only necessitated the issuance of the Standby Signal No. 1 in Hong Kong. 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 2007 was 287.5 mm. This is 61% below the normal of 737.9 mm and accounts for some 17% of the year's total rainfall of 1 706.9 mm. Pabuk which affected Hong Kong on 8-11 August brought 154.5 mm of rainfall to Hong Kong, which was the tropical cyclone bringing the most rainfall to Hong Kong in 2007. 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 AND FEBRUARY No tropical cyclone occurred over the western North Pacific and the South China Sea in January and February. MARCH Kong-rey (0701) formed as a tropical depression over the western North Pacific about 1470 km east-southeast of Guam on 31 March and moved west-northwestwards. Kong-rey intensified into a tropical storm on 1 April and moved northwestwards. It intensified into a severe tropical storm on 2 April and further into a typhoon on the next day. Kong-rey turned to move northwards on the early morning of 4 April. It then turned to the northeast and weakened into a severe tropical storm that afternoon. Kong-rey weakened further into a tropical storm on 5 April and became an extratropical cyclone over the western North Pacific to the southeast of Japan that afternoon. APRIL No tropical cyclone formed over the western North Pacific and the South China Sea in April. MAY Yutu (0702) formed as a tropical depression over the western North Pacific about 540 km south of Guam on 16 May and moved westwards. It intensified into a tropical storm and turned to a northwesterly track on the night of 17 May. Yutu continued to intensify into a severe tropical storm on the afternoon of 18 May. It further intensified into a typhoon the next day and turned to move northwards. Yutu took on a northeasterly track on 20 May and then weakened into a severe tropical storm on 22 May. It weakened further into a tropical storm on the early morning of 23 May and became an extra-tropical cyclone over the western North Pacific to the east-southeast of Tokyo that morning. JUNE No tropical cyclone occurred over the western North Pacific and the South China Sea in June. JULY Toraji (0703) developed as a tropical depression over the South China Sea about 180 km south of Haikou on the morning of 4 July and moved generally northwestwards. Toraji crossed Hainan that afternoon. It entered Beibu Wan on the morning of 5 July and then intensified into a tropical storm. Toraji made landfall near Dongxing at the coast of Guangxi that evening and weakened into an area of low pressure on the early morning of 6 July. Toraji brought heavy rain to parts of Guangxi. More than 6 700 hectares of farmland were affected and 378 houses collapsed, with another 946 houses damaged. The direct economic losses exceeded RMB$73 million. Man-yi (0704) developed as a tropical depression over the western North Pacific about 1 250 km east-southeast of Yap on 7 July and moved generally northwestwards. It intensified into a tropical storm on 9 July, a severe tropical storm the next day and further into a typhoon on 11 July. Man-yi turned to a north-northwesterly track on 12 July. It turned further northwards on 13 July and passed about 30 km west of Okinawa that morning, where the mean sea level pressure fell below 942 hPa. Man-yi turned to move northeast on 14 July and made landfall over Kyushu, Japan. It then turned to move east-northeast that night and skirted southern Shikoku. Man-yi weakened into a severe tropical storm on the morning of 15 July. It skirted the coastal waters to the south of Japan and weakened further into a tropical storm in the evening. Man-yi became an extratropical cyclone to the east of Japan on 16 July. According to press reports, Man-yi was the strongest typhoon on record to hit Japan in July since 1951. It brought torrential rain, flooding and landslides to Japan where at least 5 people were killed and 80 injured. More than 40 000 people had been evacuated. Fifteen houses were destroyed and about 1 500 flooded. Man-yi also cut off electricity supply to around 134 000 and 740 000 households respectively in Okinawa and Kyushu. Hundreds of flights were cancelled and train services were disrupted. Earlier, a Chinese freighter sank in high seas and storm force winds on 11 July when it was about 600 km northwest of Guam. Nine seamen were reported missing. Usagi (0705) developed as a tropical depression over the western North Pacific about 1 440 km southeast of Iwo Jima on 28 July and moved generally westwards. It developed into a tropical storm on 29 July and then a severe tropical storm the next day when it turned to a northwesterly track. Usagi intensified further into a typhoon on 31 July. It made landfall over eastern Kyushu, Japan on 2 August and weakened into a severe tropical storm that evening. Usagi turned northwards to cross the western part of Honshu, Japan on the early morning of 3 August. It weakened further into a tropical storm that morning and turned to move northeastwards. It became an extra-tropical cyclone on the afternoon of 4 August near Hokkaido, Japan. In the fury of Usagi, at least five people were injured and about 9 700 homes were without power supply in Japan. AUGUST A tropical depression formed over the central part of the South China Sea about 480 km south-southeast of Xisha on the early morning of 3 August and moved generally west-northwestwards. It intensified into a tropical storm the next morning and took on a north-northwesterly track on 5 August, skirting the coast of Vietnam. It weakened into a tropical depression on 6 August and further into an area of low pressure south of Beibu Wan on 7 August. Pabuk (0706) formed as a tropical depression over the western North Pacific about 1 220 km southeast of Okinawa on 5 August and moved generally west-northwestwards. It intensified into a tropical storm that evening and became a severe tropical storm the next day. Pabuk crossed the southern tip of Taiwan on the early morning of 8 August, and weakened into a tropical storm that afternoon. Pabuk skirted the seas south of Hong Kong on 9 August and weakened into a tropical depression. It turned northeastwards and intensified into a tropical storm on 10 August. Pabuk crossed the western part of Hong Kong that afternoon but turned abruptly westwards to make landfall in Zhongshan that evening and weakened into a tropical depression. It weakened into an area of low pressure inland on 11 August. Wutip (0707) formed as a tropical depression over the western North Pacific about 840 km east of Manila on 7 August. Wutip moved northwestwards and intensified into a tropical storm the next day. It weakened into a tropical depression and crossed Taiwan on the morning of 9 August. Wutip weakened further into an area of low pressure over Taiwan that day. Sepat (0708) formed as a tropical depression over the western North Pacific about 1 600 km east of Manila on 12 August and moved generally west-southwestwards. It intensified first into a tropical storm and then a severe tropical storm the next day. Sepat became a typhoon on 14 August and changed to a northwesterly track on 15 August. After crossing Taiwan and the Taiwan Strait on 18 August, Sepat made landfall near Quanzhou City, Fujian on the morning of 19 August and weakened into a tropical storm. It weakened into a tropical depression that night and further into an area of low pressure over southeastern China on 20 August. During the passage of Sepat over Taiwan, one person was killed and 24 people injured, electricity supply to more than 300 000 households were disrupted and the damage to fisheries and agriculture amounted to about HK$200 million. In Fuijan and Zhejiang, a total of 14 people were killed, one person was missing and over 60 people injured. Over 3 300 houses collapsed and the economic losses exceeded RMB$1 900 million. Figure 2.3 shows the satellite image of Sepat. Fitow (0709) formed as a tropical depression over the western Pacific about 1 090 km east-northeast of Guam on 28 August and moved north-northeastwards initially. It intensified first into a tropical storm and then a severe tropical storm the next day. Fitow turned to a northerly track and intensified further into a typhoon on 30 August. It changed to a northwesterly track on 31 August and further to a westerly track on 1 September. It weakened into a severe tropical storm on 3 September but re-intensified into a typhoon on 5 September. After turning north and crossing the eastern part of Honshu, Japan on 6 September, Fitow weakened into a severe tropical storm on 7 September. Fitow weakened further into a tropical storm that evening, and then became an extra-tropical cyclone near Hokkaido, Japan on the early morning of 8 September. SEPTEMBER Danas (0710) formed as a tropical depression over the western North Pacific about 1 920 km east of Iwo Jima on 6 September and moved generally northwestwards. It intensified into a tropical storm the next day and turned to move north-northwestwards on 9 September. Danas intensified further into a severe tropical storm on 10 September and changed to move northeastwards. It turned to move east and became an extra-tropical cyclone over the western North Pacific to the east of Japan on 11 September. Nari (0711) developed as a tropical depression over the western North Pacific about 910 km southeast of Okinawa on 13 September and moved generally northwestwards. Nari intensified into a tropical storm that afternoon and then a severe tropical storm that evening. It intensified further into a typhoon on 14 September, passing to the southwest of Okinawa that evening. Nari turned to move north on 15 September. It crossed the southeastern part of Korea and weakened into a severe tropical storm the next evening. Nari turned to move northeastwards and became an extratropical cyclone over the Sea of Japan on 17 September. Nari brought heavy rain to Korea, causing floods and landslides. At least 13 people were killed and 7 others missing. In Jeju, over 30 vessels sank or were wrecked. Electricity supply to over 50 000 households was interrupted. Wipha (0712) developed as a tropical depression over the western North Pacific about 940 km southeast of Okinawa on 15 September and moved west-northwestwards. It intensified first into a tropical storm and then a severe tropical storm the next day. Wipha intensified further into a typhoon on 17 September. It turned to move northwest on 18 September and passed to the north of Taiwan that evening. Under the fury of Wipha, one person was killed in Taiwan while another injured. Electricity supply to about 8 000 families was interrupted. Wipha made landfall near Cangnan, Zhejiang on the early morning of 19 September. It weakened into a severe tropical storm and turned to move northwards that morning, and weakened further into a tropical storm that afternoon. Wipha became an extratropical cyclone over the Yellow Sea on 20 September. Wipha brought severe damage to Zhejiang, Fujian and Jiangsu. At least 5 persons were killed and 3 others injured. Over 2.68 million people had to be evacuated. Over 9 600 houses collapsed and another 42 000 houses were damaged. The direct economic losses amounted to 6.6 billion yuan. A satellite image of Wipha is shown in Figure 2.4. Francisco (0713) developed as a tropical depression over the South China Sea about 700 km east-southeast of Hong Kong on 22 September and moved westwards. It intensified into a tropical storm on the afternoon of 23 September. After passing about 290 km to the south-southwest of Hong Kong on the early morning of 24 September, Francisco made landfall over Hainan that afternoon. Francisco weakened into a tropical depression that night and crossed Beibu Wan the next day. It made landfall and weakened into an area of low pressure over the coastal regions of northern Vietnam on the early morning of 26 September. Lekima (0714) developed as a tropical depression over the western North Pacific about 250 km northeast of Manila on 29 September. It moved westwards and entered the South China Sea that evening. Lekima changed to move west-southwestwards and intensified into a tropical storm on 30 September. Lekima intensified into a severe tropical storm on 1 October over the central part of the South China Sea and turned to move northwestwards. Under the combined effect of the northeast monsoon and Lekima, windy conditions and rough seas affected the south China coastal waters. Lekima made landfall near Sanya, Hainan on the night of 2 October and skirted the coastal waters of the southern part of Hainan. It intensified into a typhoon over Beibu Wan on the afternoon of 3 October. After making landfall over the coast of Vietnam coast that evening, Lekima weakened into a severe tropical storm. It continued to weaken into a tropical storm on the early morning of 4 October and then a tropical depression that afternoon. Lekima dissipated inland afterwards. In the fury of Lekima, more than 225 000 people had to be evacuated from low-lying areas and the direct economic losses amounted to 504 million yuan in Hainan. Lekima brought floods and landslides to Vietnam where at least 67 people were killed, over 70 000 houses were flooded or collapsed. OCTOBER Seven tropical cyclones occurred over the western North Pacific and South China Sea in October 2007. Amongst them, four of the tropical cyclones only affected the western North Pacific east of longitude 140°E. Krosa (0715) developed as a tropical depression over the western North Pacific about 1 260 km southeast of Taibei on 1 October and was almost stationary. It intensified into a tropical storm the next day. Krosa intensified first into a severe tropical storm and then into a typhoon on 3 October, and started to move northwestwards. It crossed the northern part of Taiwan on the night of 6 October. In the fury of Krosa, 5 people were killed, 2 missing and 56 people were injured in Taiwan. Electricity supplies to more than 2 million households were disrupted. Krosa crossed the Taiwan Strait on the morning of 7 October. It made landfall over the coast of southeast China between Cangnan, Zhejiang and Fuding, Fujian that afternoon and then weakened into a severe tropical storm and became slow moving. Krosa weakened into a tropical storm on the early morning of 8 October and then turned to move northeastwards. It weakened further into a tropical depression that afternoon and became an extratropical cyclone over the East China Sea that night. Krosa brought heavy rain and flooding to Zhejiang where some seven million people were affected, electricity supply to 51 villages and towns was disrupted and the economic losses amounted to 7.5 billion yuan. Figure 2.5 shows the satellite image of Lekima and Krosa. Haiyan (0716) developed as a tropical depression over the western North Pacific about 1050 km north-northeast of Wake Island on 4 October and moved eastwards. It intensified into a tropical storm the next day and turned to move northwards. Haiyan turned to a northwest track on 6 October and weakened into a tropical depression. It dissipated over the sea on 7 October. Podul (0717) formed as a tropical depression over the western North Pacific about 660 km east-southeast of Iwo Jima on 4 October and moved generally northeastwards.?It intensified into a tropical storm the next day.?Podul became an extratropical cyclone over the western North Pacific east of Japan on 6 October. Lingling (0718) formed as a tropical depression over the western North Pacific about 950 km east-northeast of Wake Island on 11 October and moved generally northwestwards. It intensified into a tropical storm the next day. Lingling weakened into a tropical depression on the early morning of 14 October and turned to move northwards. It intensified into a tropical storm again that afternoon and then turned to move northeastwards. Lingling weakened first into a tropical depression on 15 October and became an extratropical cyclone over the western North Pacific near the International Date Line. Kajiki (0719) formed as a tropical depression over the western North Pacific about 460 km north-northeast of Guam on 18 October and moved generally northwestwards. It intensified into a tropical storm on the following afternoon and a severe tropical storm on the early morning of 20 October. Kajiki intensified further into a typhoon on the morning of 20 October and turned to move northwards. It accelerated towards northeast the following day. Kajiki weakened into a severe tropical storm on 22 October and then became an extratropical cyclone over the western North Pacific. Faxai (0720) developed as a tropical depression over the western North Pacific about 1 110 km southeast of Okinawa on 25 October and moved northwestwards. It intensified into a tropical storm on the following day and turned to move northwards. Faxai intensified further into a severe tropical storm on 27 October and passed to the east of Japan that evening. It became an extratropical cyclone over the western North Pacific to the east of Japan that night. NOVEMBER Peipah (0721) formed as a tropical depression over the western North Pacific about 890 km east-northeast of Manila on 3 November and moved west-southwestwards. It intensified into a tropical storm on the early morning of 4 November and then a severe tropical storm that afternoon. After crossing Luzon on a west-northwest track that night, Peipah entered the South China Sea on the morning of 5 November and slowed down. It turned northwestwards that night and then intensified into a typhoon the next day. Under the combined effect of Peipah and the northeast monsoon, it was rather windy over the northern part of the South China Sea. Peipah turned to move southwestwards on 7 November. It weakened into a severe tropical storm that afternoon and then into a tropical storm that evening. After weakening into a tropical depression on the morning of 9 November, Peipah dissipated over the coastal waters of Vietnam that evening. Peipah caused seven deaths in the Philippines and left 600 000 people without electricity there. Tapah (0722) formed as a tropical depression over the western North Pacific about 480 km south of Iwo Jima on 11 November and moved generally northeastwards. It intensified into a tropical storm on 12 November. Tapah weakened into a tropical depression on the early morning of 13 November and then became an extra-tropical cyclone over the western North Pacific to the east-northeast of Iwo Jima that morning. Mitag (0723) formed as a tropical depression over the western North Pacific about 1 810 km east of Manila on 20 November and moved generally west-northwestwards. It intensified into a tropical storm the next morning. Mitag intensified first into a severe tropical storm and then a typhoon on 22 November and move westwards. It turned to move northwest on the evening of 23 November. After crossing Luzon on 26 November, Mitag turned to move north-northwest over the Luzon Strait that day. Mitag turned to move east on 27 November. It weakened gradually on that day into a severe tropical storm in the morning, a tropical storm that afternoon, and then a tropical depression that night. Mitag weakened into an area of low pressure over the western North Pacific on 28 November. In the Philippines, eight people were killed and two reported missing. Around 1 000 hectares of rice crops were flooded. Hagibis (0724) formed as a tropical depression over the central part of the South China Sea about 510 km east of Nansha on 20 November and moved westwards. It intensified into a tropical storm on the morning of 21 November and then into a severe tropical storm on the early morning of 22 November. Hagibis slowed down on 23 November and turned to move eastwards the next day. It weakened into a tropical storm on 25 November. After crossing the central Philippines on 27 November on an east-northeasterly track, Hagibis weakened into a tropical depression on the early morning of 28 November and then into an area of low pressure over the western North Pacific that day. In the Philippines, 14 people were killed under the influence of Hagibis. A Philippine fishing boat capsized in the South China Sea and 25 crewmen were missing. Figure 2.6 shows the satellite image of Mitag and Hagibis.
DECEMBER No tropical cyclone occurred over the western North Pacific and the South China Sea in December.
Note: Casualties and damage figures were compiled from press reports. - Top - |