ENG-1970 — Page 273

GEOGRAPHY AND CLIMATE

THE ROYAL OBSERVATORY

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The main function of the Royal Observatory today is the pro- vision of meteorological services. Weather forecasts and tropical cyclone warnings are prepared in the Royal Observatory while services for aviation are provided at the Airport Meteorological Office.

Close liaison is maintained with all ships that visit Hong Kong and about 60 selected ships are provided with instruments by the Observatory to encourage them to transmit weather reports which are used for locating tropical cyclones and in the preparation of forecasts. About 75 weather reports are received each day from ships, through two radio coast stations in Hong Kong. All reports received are disseminated to other centres through the new World Weather Watch telecommunication network. In addition about 5,000 weather reports from land stations and ships are received each day from other countries. They are decoded, plotted and analysed at the Royal Observatory. Special weather bulletins are broadcast for shipping and for fishermen, and all aircraft leaving Hong Kong are given briefings, written forecasts and weather charts.

One of the most important functions of the Royal Observatory is to issue warnings of Tropical Cyclones. Whenever a Tropical De- pression, Tropical Storm or Typhoon is located within the region bounded by latitudes 10°-30° north and longitudes 105°-125° east, six-hourly and often three-hourly non-local warnings are issued. These provide information on the maximum winds, the position and movement of the centre and the forecast position 24 hours ahead. Reports from ships and reconnaissance aircraft and cloud pictures received at the Royal Observatory direct from meteorological satel- lites are used to locate the storm.

When the Colony itself is threatened warnings are widely distrib- uted by means of visual signals, telephone, radio and television. Statements and recommended precautions are broadcast at frequent intervals whenever local signals are displayed. The Royal Observa- tory also issues 'Thunderstorm and heavy rain warnings', 'Grass fire warnings', and 'Frost and low temperature warnings' whenever

necessary.