Newsletter For Hong Kong Voluntary Observing Ships No.19/ July 2003 120 Years of Service for the Hong Kong Marine Community Year 2003 marks the 120th anniversary of the Hong Kong Observatory (HKO). The figure of 120 years carries a special meaning in Chinese calendar and time keeping as it equals two cycles of the "Heavenly Stems and Earthly Branches", a sign of blessed completeness. As early as 1884, HKO employed a system of drum, ball and cone to warn mariners of tropical cyclone on the South China Sea. To serve the needs of ocean-going merchant ships for accurate sea navigation, HKO made use of a six-inch Lee Equatorial telescope to determine the local time accurately and helped shipmasters calibrate their ship chronometers. In the early development of marine meteorological services, weather observations taken by merchant ships were nearly the only information available to assess the location and intensity of tropical cyclones on the sea. To collect logbook data and serve the increasing number of vessels entering the harbour, HKO appointed Ms. Annie Doberck in 1892 to liaise with shipping companies and to extract meteorological reports from navigation logs, who could be considered as the first port meteorological officer in Hong Kong. The Voluntary Observing Ships (VOS) scheme in Hong Kong dates back to 1949. Through the years, weather observations taken by VOS have played an important part in the preparation of weather forecasts and warnings for shipping and the local community, particularly in the provision of tropical cyclone warning services. Although the emergence of remote sensing technologies such as meteorological satellites and radars have brought about leap improvements in weather forecasting, ship weather observations remain among the most crucial information as these are "ground" truth data presented to the forecasters and computer weather prediction models. In line with its fine tradition of providing quality weather service in steps with the development of the community, HKO will continue to work with the VOS fleet and other partners to improve its weather forecast and warning services in the 21st century. The ultimate goal is the reduction of loss of life and property in inclement weather, and the betterment of the community. Enhancement of Tropical Cyclone Warnings for Shipping From 30 May 2003 onwards, HKO's tropical cyclone track forecasts given in the tropical cyclone warnings for shipping cover a period up to 72 hours ahead, providing more information than the original 48 hours forecast. Such enhancement has become possible because of advances in numerical weather prediction models in recent years. HKO issues tropical cyclone warnings for shipping every three hours at around 0200, 0500, 0800, 1100, 1400, 1700, 2000 and 2300 UTC when a tropical cyclone is located within the area bound by latitudes 10N and 30N, and longitudes 105E and 125E. The warnings are broadcast to ships by the Hong Kong coast radio station via NAVTEX. Repeat messages are broadcast at 0150, 0550, 0950, 1350, 1750 and 2150 UTC. Warnings, track and positions of tropical cyclones are also available on HKO's web site: www.hko.gov.hk/informtc/informtc.htm Ship joining the fleet of HKVOS A container named "OCL Shenzhen" about 100,000 DWT has joined the fleet of HKVOS since May 2003. We are grateful to Captain C. F. Lum for his support to the HKVOS scheme. Other ships calling at Hong Kong on a regular basis are welcome to join the HKVOS fleet. Please contact our PMO for more information or return the completed recruitment form which is available on the following website : www.hko.gov.hk/wservice/tsheet/pms/images/HKVOS_recruit_e.pdf International Training Courses in Marine Meteorology Under the Voluntary Cooperation Programme of the World Meteorological Organization (WMO), HKO hosted two international training courses in marine meteorology for 11 overseas trainees in 2002 to help them enhance the marine weather services in their home countries. Topics covered in these courses included the VOS scheme, port meteorological services, physical oceanography, public weather services, and satellite and radar meteorology. These courses form part of the strategy of the WMO in enhancing the capacity of National Meteorological Services. Summary of Tropical Cyclones over the South China Sea in 2002 Seven tropical cyclones affected the South China Sea, the area bounded by 10N and 25N, 105E and 120E, in 2002, which is significantly less than the normal figure of 12 a year. All these tropical cyclones formed either in the South China Sea or over the Philippines. No tropical cyclones from the northwest Pacific moved into the South China Sea. This was probably due to a change in the atmospheric circulation pattern in connection with the El Nino in 2002. The following is a brief summary of four tropical cyclones that brought gale force wind or above to the busy shipping lanes over the South China Sea in 2002: Nakri formed as a tropical depression (TD) about 150 km northeast of Dongsha Dao over the northern part of the South China Sea on 8 July 2002. It moved slowly northeastwards and strengthened into a tropical storm (TS) the next day. After traversing the west coast of Taiwan, it made landfall near Taibei on 10 July. Nakri then moved east away from Taiwan. It changed its course towards north near the Ryukyu Islands on 12 July and became an extratropical cyclone over the East China Sea the following day. Kammuri developed as a TD over the northern part of the South China Sea, about 400 km east-southeast of Hong Kong on 3 August. It tracked westwards and strengthened into a TS the next day. Kammuri then slowed down and abruptly turned to the north-northeast towards the eastern part of Guangdong. On 5 August, it intensified into a severe tropical storm (STS). After making landfall near Shanwei, Kammuri moved northwards and weakened gradually into an area of low pressure over Jiangxi Province that night. Vongfong developed as a TD about 280 km south-southeast of Xisha Dao on 15 August. It moved slowly to the northeast in the first two days and turned to the west-northwest on 17 August. Vongfong intensified into a TS and moved towards the north-northwest on 18 August. It accelerated towards the west coast of Guangdong on 19 August and intensified into an STS that afternoon. Vongfong skirted the northeastern coast of Hainan and then made landfall near Zhangjiang the same night. After landfall, it weakened rapidly and dissipated over Guangxi on 20 August. Hagupit developed as a TD about 140 km southeast of Dongsha Dao on 10 September and moved steadily west-northwest over the northern part of the South China Sea. It intensified rapidly into a TS the same night and became an STS on 11 September. At 0000 UTC the same day, the HKVOS "OOCL Chicago" (call sign VRWQ2) reported 30 knots northwesterly winds about 75 km west of Hagupit. On 12 September, Hagupit made landfall near Yangjiang in western Guangdong and weakened into a TS. It then turned west and weakened further into a TD that night. On 13 September morning, Hagupit weakened into an area of low pressure over the coastal areas of Guangxi. List of tropical cyclones affecting the South China Sea in 2002 Name of tropical cyclone Formation Dissipation Maximum sustained wind speed near the centre(km/h) Minimum sea-levelpressure(hPa) Typhoon Noguri 6/6 11/6 120 970 Tropical Storm Nakri 8/7 13/7 75 985 Tropical Depression 20/7 22/7 55 1000 Severe Tropical Storm Kammuri 3/8 5/8 100 975 Severe Tropical Storm Vongfong 15/8 20/8 90 980 Severe Tropical Storm Hagupit 10/9 12/9 110 980 Tropical Storm Mekkhala 23/9 28/9 75 992