A Brief Overview of the Hong Kong Observatory

• http://www.weather.gov.hk/

• 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)• http://www.weather.gov.hk/wxinfo/currwx

/current.htm

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• http://www.weather.gov.hk/wxinfo/currwx/f5d.

htm

Warnings

• http://www.weather.gov.hk/textonly/explain/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.

• http://www.weather.gov.hk/wservice/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.

• http://www.weather.gov.hk/wservice/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.

• http://www.weather.gov.hk/wservice/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.

• http://www.weather.gov.hk/wservice/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.

• http://www.weather.gov.hk/wservice/warning/smse.htm

• This warning is issued whenever ground frost is expected to occur on high ground or inland in the New Territories.

• http://www.weather.gov.hk/wservice/tsheet/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.

• http://www.weather.gov.hk/wservice/tsheet/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.

• http://www.weather.gov.hk/wservice/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.

• http://www.weather.gov.hk/informtc/informtc.htm

Wind Speeds

Description Beaufort Force Wind Speed (km/h)

Light 1-2 2-12

Moderate 3-4 13-30

Fresh 5 31-40

Strong 6-7 41-62

Gale 8-9 63-87

Storm 10-11 88-117

Hurricane 12 >118

Classification

ClassMaximum Sustained Wind Speed (km/h)

Tropical Depression <63

Tropical Storm 63-87

Severe Tropical Storm 88-117

Typhoon >118

Warning Signals

• http://www.weather.gov.hk/informtc/tcsignal.htm

Name

Standby Signal 1

Strong Wind Signal 3

Northwest Gale or Storm Signal 8NW

Southwest Gale or Storm Signal 8SW

Northeast Gale or Storm Signal 8NE

Southeast Gale or Storm Signal 8SE

Increasing Gale or Storm Signal 9

Hurricane Signal 10

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.

• http://www.weather.gov.hk/informtc/sound/tcname2000e.htm

Other Services

• Tidal Information• Seismology: monitor earthquake activities

around Hong Kong• Time Service: provide accurate time service

with atomic clock• Astronomy: times of rise and set of the Sun,

the Moon and planets, times of eclipses, etc• Radiation Monitoring