THE ENVIRONMENT
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Weather Monitoring and Forecasting
To provide weather forecasts and warnings of hazardous weather, the Royal Observatory maintains a close meteorological watch around the clock. The Observatory exchanges weather observations with the rest of the world through the Global Telecommunications System operated under the auspices of the World Meteorological Organisation. Through its telecommunication lines with meteorological centres in Beijing, Tokyo and Bangkok, about 20 000 weather reports are received each day.
Hourly cloud pictures received from the Geostationary Meteorological Satellite of the Japan Meteorological Agency give general indications of tropical cyclones, severe storms and frontal systems approaching the South China coast. The Observatory's weather radar system at Tate's Cairn detects rain within about 500 km of Hong Kong and gives estimates of rain intensity and movement. Information on thunderstorms as detected by a lightning location system is also available to forecasters.
Weather observers and automatic weather stations at about 40 locations in Hong Kong provide comprehensive and real-time coverage of regional weather variations, while observations from Voluntary Observing Ships provide valuable information on weather at sea.
Rainfall information is important because of the territory's vulnerability to floods and susceptibility to landslips during heavy rain. A dense network of about 70 automatic reporting rain-gauges provides real-time information on rain distribution. and intensity over Hong Kong for the operation of rainstorm, flood and landslip warnings.
The Observatory operates tide gauges for monitoring coastal flooding and raised sea levels caused by tropical cyclones. To probe the atmosphere aloft, radiosondes carried by balloons are launched four times a day at King's Park to relay weather information from the upper air.
The Observatory exchanges weather radar images with the Guangdong Meteorological Bureau and operates three automatic weather stations at Huangmao Zhou and the Tuoning Islands in Chinese waters. More stations will be set up in the Pearl River estuary area to give earlier indication and better timing of the approach of hazardous weather such as fronts, squall lines and tropical cyclones. Using guidance from numerical products from both global and limited area models, forecasters can now issue weather forecasts several days ahead with reasonable confidence.
Aviation Meteorology
The Royal Observatory operates the Airport Meteorological Office (AMO) at the Hong Kong International Airport to provide services for civil aviation. Besides keeping watch and warning of hazardous weather over the Hong Kong Flight Information Region, the AMO provides flight documentation to aircraft departing Hong Kong. This includes weather forecasts for destination aerodromes, prognostic charts of significant weather en route and forecast wind and temperature data appropriate to cruising levels.
The Observatory is setting up meteorological facilities for the new airport at Chek Lap Kok. State-of-the-art equipment being installed includes a terminal Doppler weather radar to detect wind shear due to thunderstorms.