Newsletter For Hong Kong Voluntary Observing Ships No.18/ April 2002 Websites on Official World Weather Information developed by HKO The World Meteorological Organization (WMO) decided in the year 2000 to set up websites to provide authentic and official world weather information to the international public. In view of our expertise in website management and our well established experience in providing public weather services, the Hong Kong Observatory was tasked by WMO to develop and maintain two pilot websites on world weather: the World Weather Information Service (WWIS) website provides climatological information and official weather forecasts of cities all over the world while the Severe Weather Information Centre (SWIC) website provides official information and warnings on severe weather round the world. The WWIS website will be implemented in phases. It currently delivers climatological information of cities and provides links to the websites of individual National Meteorological Services (NMSs). The next phase will include official forecasts issued by the respective NMSs and is expected to start operational trial before the end of 2002. The SWIC website will provide, as a first step, official forecasts and warnings of tropical cyclones in the western North Pacific issued by NMSs in the region. Up-to-date information on tropical cyclones in the form of advisories and warnings from participating countries are displayed, enabling visitors to the site to gain a better appreciation of the potential impact of tropical cyclones that transcend national boundaries. The two websites have already commenced trial operation. You are welcome to visit the websites. Their URLs are: www.worldweather.org (for WWIS) typhoon.worldweather.org (for SWIC) Summary of Tropical Cyclones over the South China Sea in 2001 A total of 12 tropical cyclones affected the South China Sea in 2001. Four formed in-situ while the other eight originated from the western North Pacific. Seven of these 12 tropical cyclones attained typhoon strength. Typhoon Nari was the tropical cyclone with the most unusual track in 2001. During its long life span of 15 days, Nari strengthened and weakened four times. Under a weak steering flow and the Fujiwhara effect, Nari looped in an anti-clockwise direction near the Ryukyu Islands at first. The eastward extension of an anticyclone over China induced Nari to move from northeast to southwest. It traversed Taiwan and then entered the South China Sea. Nari made landfall over eastern Guangdong and finally dissipated inland. A brief review of four typhoons which brought gale force winds to the busy shipping lanes in the South China Sea is described below. Detailed information on other tropical cyclones can be found at the Hong Kong Observatory's website (www.weather.gov.hk/informtc/informtc.htm). Utor formed as a tropical depression (TD) about 340 kilometres (km) south of Yap on 1 July 2001. Moving northwards, it intensified into a tropical storm (TS) the next day. Utor then tracked northwestwards at a high speed of about 38km/h and became a typhoon on the afternoon of 3 July. After traversing the Luzon Strait, Utor entered the South China Sea and headed toward the coast of Guangdong on 5 July. It made landfall near Shanwei and weakened into a severe tropical storm (STS) on the morning of 6 July. Moving generally westwards across Guangdong, Utor weakened gradually into a TD on 7 July and dissipated the next morning while entering Guangxi. Yutu developed into a TD about 600 km northeast of Manila on 23 July. Moving west-northwestwards, it intensified into a TS over the Luzon Strait that evening. Yutu then took on a more westward course and deepened into a STS while entering the South China Sea on 24 July. It intensified rapidly into a typhoon that evening. Yutu then weakened into a STS and made landfall near Zhanjiang on the morning of 26 July. Moving further inland, Yutu became an area of low pressure that night. Nari developed into a TD about 220 km east of Taibei on the early morning of 6 September. It moved northeastwards and deepened into a TS that afternoon. Nari became slow-moving and intensified into a STS on 7 September after traversing Okinawa. Then, it made three anti-clockwise loops near the Ryukyu Islands and attained typhoon intensity on two separate occasions in the following week. Nari started to head southwest on 14 September. It regained typhoon intensity for the third time the next day and tracked towards Taiwan. After sweeping across Taiwan, Nari weakened rapidly into a TS on 17 September. It entered the northern part of South China Sea and moved westwards on 19 September. Nari re-intensified into a STS before landing near Shantou at around noon on 20 September. That night, it weakened gradually and dissipated over inland Guangdong. Lingling formed as a TD about 750 km southeast of Manila on 6 November, and tracked west-northwestwards across the southern Philippines. It intensified into a TS on 7 November and deepened further into a STS the next day. After entering the South China Sea on 9 November, Lingling attained typhoon strength and took on a westward track. On the morning of 12 November, Lingling weakened into a STS before making landfall over central Vietnam. Lingling moved inland later that day and weakened rapidly. It became an area of low pressure over northern Cambodia that night. List of tropical cyclones affecting the South China Sea in 2001 Name of tropical cyclone Start date End date Maximum sustained wind speed near the centre (km/h) Minimum sea-level pressure (hPa) Severe Tropical Storm Cimaron 10/5 14/5 90 985 Typhoon Chebi 20/6 24/6 140 960 Typhoon Durian 30/6 3/7 130 965 Typhoon Utor 1/7 7/7 130 965 Tropical Storm Trami 9/7 12/7 75 994 Typhoon Yutu 23/7 26/7 150 960 Typhoon Toraji 26/7 31/7 130 965 Tropical Storm Usagi 9/8 11/8 75 992 Tropical Storm Fitow 28/8 31/8 65 985 Typhoon Nari 5/9 20/9 150 955 Typhoon Lingling 6/11 12/11 155 950 Tropical Storm Kajiki 5/12 9/12 65 996 Ships joining the fleet of Hong Kong Voluntary Observing Ships (HKVOS) "Harmony Container" a container of about 17,600 gross tonnage and "SuperStar Leo" a cruise ship of about 75,300 gross tonnage joined the fleet of HKVOS in August 2001 and December 2001 respectively. Weather reports from these two ships have been regularly received by the Hong Kong Observatory since their recruitment. These weather reports provide valuable information over the sea areas to help the duty forecasters in preparing weather forecasts and warnings for the shipping community. We highly appreciate the support from Captain Subir Mital of the "Harmony Container" and Captain Lars Bengtsson of the "SuperStar Leo". Ships calling at Hong Kong on a routine basis are welcome to join the HKVOS. Please contact our Port Meteorological Officer (PMO) for more information or return the completed recruitment form which is available on the website (www.weather.gov.hk/wservice/tsheet/pms/images/HKVOS_recruit_e.pdf). Review of meteorological instruments on loan to HKVOS In order to improve the quality of ship weather reports, the Hong Kong Observatory will conduct regular reviews on the condition of meteorological instruments on loan to HKVOS. Shipmasters will be requested to check and inform our PMO whether the meteorological instruments onboard are functioning properly. The Hong Kong Observatory will arrange prompt replacement of malfunctioned instruments.