Warning Signs from the Hong Kong Observatory
1. Overview of warning signals ① Tropical cyclone warning
Since 1884, when a tropical cyclone approaches Hong Kong, the Hong Kong Observatory will issue a tropical cyclone warning signal to warn the public that a tropical cyclone is approaching. Wind threats posed by general areas of Hong Kong. The current tropical cyclone warning signals are divided into five levels, namely No. 1, No. 3, No. 8 (divided into four northeast, northwest, southwest and southeast), No. 9 and No. 10.
②Heavy Rain Warning System
The Hong Kong Heavy Rain Warning Signal is a warning signal issued by the Hong Kong Observatory to remind and warn the public when heavy rain occurs or is forecast to occur in Hong Kong. In 1992, the Hong Kong Observatory established a color-coded four-level rainstorm warning system. In 1998, the heavy rain warning system was revised to three levels: yellow, red and black.
③Landslip Warning
When the Hong Kong Observatory, with reference to the advice of the Geotechnical Engineering Office under the Civil Engineering and Development Department, believes that continued heavy rain is very likely to cause landslips, the Observatory A landslip warning will be issued. This warning mainly targets landslip situations that are numerous and have widespread impacts.
④Special Report on Flooding in the Northern New Territories
Whenever flooding has occurred or is expected to occur in low-lying areas in the northern New Territories, the Observatory will issue a special report on flooding in the northern New Territories.
⑤Thunderstorm Warning
Whether the thunderstorm affects a wide range of areas or only affects a certain area in Hong Kong, the Observatory will issue a thunderstorm warning. Hong Kong's outdoor sports grounds, courts and swimming pools are customarily closed to avoid accidents. Thunderstorm warnings are the most frequent warning signals issued in a year. During the rainy season, they may even be issued multiple times in one day.
⑥Strong Monsoon Signal
A strong monsoon signal indicates that the average wind speed of the winter or summer monsoon is or will be at any place close to sea level in Hong Kong. It will exceed 40 kilometers per hour. Winter monsoon winds generally blow from the north or east, while summer monsoon winds are mainly southwesterly winds. In very open areas, monsoon wind speeds can exceed 70 kilometers per hour.
Hong Kong Observatory
⑦Cold and Very Hot Weather Warning
Starting from December 1999, when the minimum temperature in urban areas is forecast to drop to 12.0 degrees Celsius or below , the Hong Kong Observatory will issue a cold weather warning; in 2000, a very hot weather warning will also be issued, which will be issued when the maximum temperature in the urban area is forecast to rise to 33.0 degrees Celsius or above. ⑧Frost Warning
The weather in Hong Kong is cold in winter. When the dew point drops to close to or below 0 degrees Celsius and the wind is weak, ground frost may occur in the mountains and inland areas of the New Territories. When there are signs of ground frost in the high mountains of Hong Kong or in the inland areas of the New Territories, the Observatory will issue a frost warning to alert farmers of the impact of ground frost on crops.
⑨Fire Hazard Warning
The Hong Kong Observatory will provide information on drying conditions of vegetation based on factors conducive to the occurrence and spread of fire, such as low humidity, high wind speed and the Agriculture, Fisheries and Conservation Department. , issuing a fire hazard warning. There are two types of warnings: yellow and red. A yellow fire danger warning indicates a high fire risk, while a red fire danger warning indicates an extremely high fire risk.
⑩Tsunami Warning
A tsunami warning indicates that a violent earthquake is expected to produce or has produced a tsunami. If the tsunami continues, it will reach Hong Kong within 3 hours, and the tsunami height may exceed the normal tide height by 0.5 meters. The tsunami warning was never required to be issued, but at noon on April 3, 2007, the Observatory mistakenly stated in the "Hourly Temperature and Humidity Report" that a tsunami warning was in effect due to a manual error.
After the South Asian tsunami in December 2004, the Observatory will issue a "tsunami report" when there is a tsunami threat in the Pacific or South China Sea, but it is not expected to seriously affect Hong Kong. On the night of December 26, 2006, a strong earthquake occurred in Taiwan, and the Observatory issued a tsunami report for the first time.