A Brief Overview of the Hong Kong Observatory An official department of the Government of the Hong Kong Special Administrative Region forecasts weather and issues warnings on weather-related hazards

Observations Weather Bulletin Weather Report Weather Forecast Warnings Tropical Cyclone Other services

Observations Surface observations in headquarters, King’s Park and airport 67 automatic weather stations located in various places

Balloon-borne measurement regularly Weather radar at Tai Mo Shan, Tate’s Cairn and Tai Lam Chung Information exchange with other stations

Weather Bulletin Hourly Temp. Relative humidity UV index Regional weather (temp. and rainfall) Weather information for south china coastal waters (general condition and wind)

Weather Reprot Daily General condition, e.g sunny, partly cloudy, etc Weather map High and low temperature Relative humidity range Wind, direction and speed

Amount of rainfall UV index, highest and average Warnings, if any

Weather Forecast Next day and 5-day By supercomputer General condition, e.g. sunny, rainy, etc Wind, direction and speed High and low temperature Relative humidity range mhttp:// m

Warnings n/intro.htmhttp:// n/intro.htm Rainstorm warning signals Amber: Heavy rain has fallen or is expected to fall generally over Hong Kong, exceeding 30 millimetres in an hour. Red: Heavy rain has fallen or is expected to fall generally over Hong Kong, exceeding 50 millimetres in an hour, and is likely to continue.

Black: Very heavy rain has fallen or is expected to fall generally over Hong Kong, exceeding 70 millimetres in an hour, and is likely to continue. warning/rainstor.htmhttp:// warning/rainstor.htm

Thunderstorm warnings issued by the Observatory are intended to give short term (four hours or less) notice of the likelihood of thunderstorms affecting any part of Hong Kong. warning/thunder.htmhttp:// warning/thunder.htm

A Special Announcement on Flooding in the Northern New Territories will be issued by the Hong Kong Observatory whenever heavy rain affects the area and flooding is expected to occur or is occurring in the low-lying plains of northern New Territories. warning/flood.htmhttp:// warning/flood.htm

A landslip warning will be issued by the Hong Kong Observatory whenever the Geotechnical Engineering Office expects a high chance of many landslips as a result of persistent heavy rainfall. warning/landslip.htmhttp:// warning/landslip.htm

It is hoisted when winds associated with the summer or winter monsoon are blowing in excess of or are expected to exceed 40 kilometres per hour near sea level anywhere in Hong Kong. warning/smse.htmhttp:// warning/smse.htm

This warning is issued whenever ground frost is expected to occur on high ground or inland in the New Territories. sheet/pubwx.htm#frosthttp:// sheet/pubwx.htm#frost

A fire danger warning is issued whenever the relative humidity of the atmosphere is below certain criteria and when the vegetation is dry. A yellow fire danger warning indicates that the fire risk is high while a red fire danger warning indicates that the fire risk is extreme. sheet/pubwx.htm#firehttp:// sheet/pubwx.htm#fire

It issues warnings whenever Hong Kong is threatened by cold or very hot weather, to alert members of the public to the danger of low body temperature or the risk of heatstroke and sunburn due to cold weather or very hot weather respectively. warning/coldhot.htmhttp:// warning/coldhot.htm

Tropical Cyclones On average, there are about 6 to 7 tropical cyclones or typhoons every year entering 800km from Hong Kong. The Observatory will issue warnings to alert the general publics. tc.htmhttp:// tc.htm

Wind Speeds DescriptionBeaufort ForceWind Speed (km/h) Light Moderate Fresh Strong Gale Storm Hurricane12>118

Classification Class Maximum Sustained Wind Speed (km/h) Tropical Depression<63 Tropical Storm63-87 Severe Tropical Storm Typhoon>118

Warning Signals l.htmhttp:// l.htm Name Standby Signal1 Strong Wind Signal3

Northwest Gale or Storm Signal8NW Southwest Gale or Storm Signal8SW Northeast Gale or Storm Signal8NE Southeast Gale or Storm Signal8SE Increasing Gale or Storm Signal9 Hurricane Signal10

Names of Typhoons Before Dec 31, 1999, tropical cyclones in the western north pacific were named by U.S.A. With effect from Jan 1, 2000, each name in a list will be used in turn. The names in the list are suggested by various countries. tcname2000e.htmhttp:// tcname2000e.htm

Other Services Tidal Information Seismology: monitor earthquake activities around Hong KongSeismology Time Service: provide accurate time service with atomic clockTime Service Astronomy: times of rise and set of the Sun, the Moon and planets, times of eclipses, etcAstronomy Radiation Monitoring