Typhoons are giant storms which may cover areas of up to 500 miles in diameter and generate winds up to 180 miles an hour, have caused extensive human injury, loss of life, and untold damage to property in Hong Kong over the years. It is important to know what you may face during the season and what precautions to take when a storm is imminent.
The Hong Kong Government has a very effective system whereby information and instructions on tropical storms and typhoon activity is disseminated. With the help of local news media and the Hong Kong Observatory's website, the Government reports the location of the storm, its direction and wind velocity, and how near the eye is expected to come to Hong Kong. Here are the important signal levels:
- Signal No. 1
Stand By: A tropical cyclone, centered within 800 km (500 miles) of Hong Kong, may pass and cause strong winds, gale, storm or typhoon force conditions.
- Signal No. 3
Strong Wind: Winds up to 38 M.P.H. velocity have been reported or are expected soon.
- Signal No. 8
Gale or Storm: Winds between 39 and 73 M.P.H. velocity have been reported or are expected soon. Wind direction is as follows:
8 NW From the NW quadrant.
8 SW From the SW quadrant.
8 NE From the NE quadrant.
8 SE From the SE quadrant.
- Signal No. 9
Increasing Gale or Storm: A marked increase (over 73 M.P.H.) in wind force is being experienced or is expected.
- Signal No. 10
Typhoon: Hurricane force winds are imminent from any direction. Winds could exceed well over 100 M.P.H.
English-Language Information Sources
Simply knowing what signal is issued is not enough. You should also listen to radio and TV broadcasts of weather bulletins and follow the advice given:
- Radio: 97.6 FM. RTHK Radio 3, Metro and Commercial English stations may also prove useful. Note that some FM stations are transmitted on different but nearby frequencies over different parts of the SAR.
- ATV World and TVB Pearl are Hong Kong's English language TV stations.
- Hong Kong Observatory
Bulletins will report on the weather situation about every two hours when signals 1 through 3 are in effect. When signals 8 through 10 are up, radio and TV stations will extend hours of operation to 24 hours daily and will broadcast updates at two minutes to the hour and half past the hour. In addition, local television channels will display a small signal in the upper corner of the screen noting the current signal level. If severity of the situation should warrant, additional warnings will be broadcast on the quarter hour. Information is continually available through the Hong Kong Observatory's website.
- make sure you have food and water on hand for a 48-hour period.
- Make sure there is an adequate supply of flashlights and/or lamps with sufficient batteries or fuel on hand to cover a power outage.
- At Signal 1 make sure all windows and glass doors are firmly closed.
- Set your freezer to the coldest temperature setting to minimize spoilage if the power is cut off.
- At Signal 3 close security shutters if you have them; at Signal 8 also close blinds and curtains.
- Watch for leaks around windows and doors. If the wind is strong enough, water may be blown into your home even if the windows are closed. Have handy towels, rags and mops.
- Bring flowerpots, furniture and other loose objects indoors. Tie down any outdoor object that cannot be moved.
- Keep one window opposite the wind side open. This will compensate for the differences of indoor and outdoor air pressure.
- If the storm becomes severe, move into a hallway or area where there is the least exposure to external glass windows.
- If a window breaks, place a mattress or sofa seat over the broken pane and secure it there with a heavy piece of furniture.
- Check for electrical, gas and fire hazards and make spot checks during the storm.
- Check your first aid kit.
- Check to make sure all balcony or roof drains are unobstructed. During periods of heavy rain, drains should be checked periodically.
- Remember that typhoons have "eyes", areas in their center where the weather appears calm. If the eye passes over your area, it may appear that the storm has finished, with winds then picking up again as the remainder of the storm arrives.
- After the storm is over, check for broken glass, fallen trees and downed power lines which may present safety hazards near children's school bus stops, outdoor trash areas, around your car, etc.
- In case of severe injury requiring outside assistance or ambulance service, dial 999.
The wet season in Hong Kong is normally between April and September. Rain can be particularly heavy and persistent during May and June, causing severe traffic disruption and on occasion floods and landslides.
The Hong Kong Government maintains a Rainstorm Warning System to provide timely warning and advice to the public, and to ensure a state of readiness within the essential services when dealing with emergencies that may arise from heavy rainstorms.
Rainstorm warnings operate on a color-coded warning system separate from other severe weather warnings. The Hong Kong Government Rainstorm Warning System uses three colors: AMBER, RED and BLACK.
The AMBER signal gives alert about potential heavy rain that may develop into RED or BLACK signal situations. There will be flooding in some low-lying and poorly drained areas. Key Government departments and major transport and utility operators are put on alert.
The RED and BLACK signals warn the public of heavy rain which is likely to bring about serious road flooding and traffic congestion. They will trigger response actions by Government departments and major transport and utility operators. The public will be given clear advice on the appropriate actions to take.
Once issued, the signals are broadcast over radio and television. For your own safety, listen to radio or television announcements for the latest information.
More details are available at Rainstorm Warning System.
Tsunamis are ocean waves produced by earthquakes or underwater landslides. The word is Japanese and means "harbor wave," because of the devastating effects these waves have had on low-lying Japanese coastal communities.
Tsunamis are often incorrectly referred to as tidal waves, but a tsunami is actually a series of waves that can travel at speeds averaging 450 (and up to 600) miles per hour in the open ocean. In the open ocean, tsunamis would not be felt by ships because the wavelength would be hundreds of miles long, with an amplitude of only a few feet. This would also make them unnoticeable from the air. As the waves approach the coast, their speed decreases and their amplitude increases. Unusual wave heights have been known to be over 100 feet high. However, waves that are 10 to 20 feet high can be very destructive and cause many deaths or injuries.
The Pacific Tsunami Warning Center (PTWC) is responsible for providing warnings to international authorities, Hawaii, and U. S. territories within the Pacific basin. All tsunamis are potentially dangerous, even though they may not damage every coastline they strike. The PTWC may issue the following bulletins through their web site:
A tsunami was or may have been generated, which could cause damage; therefore, people in the warned area are strongly advised to evacuate.
A tsunami was or may have been generated, but is at least two hours travel time to the area in watch status. Local officials should prepare for possible evacuation if their area is upgraded to a warning.
An earthquake has occurred in the Pacific basin, which might generate a tsunami. WC/ATWC and PTWC will issue hourly bulletins advising of the situation.
A message with information about an earthquake that is not expected to generate a tsunami. Usually only one bulletin is issued.
Be familiar with the tsunami warning signs. A strong earthquake near the coast may generate a tsunami. Tsunamis most frequently come onshore as a rapidly rising turbulent surge of water choked with debris. They are not V-shaped or rolling waves, and are not "surfable."
Last modified: October 4, 2005