Rainstorm warning system caters to entire city rather than individual districts: former HKO assistant director

It is not applicable for the Hong Kong Observatory to issue a Black rainstorm signal based on torrential rainfall in specific districts, as the warning system is designed to cater to the entire city rather than particular districts, said the former assistant director of observatory Leung Wing-mo.

His comment came after some questioned the weather watchdog as to why a Black rainstorm signal was not issued when Tseung Kwan O recorded more than 400 millimeters of rainfall last Saturday (May 4). Over a hundred cars in open-air parking lots were halfway submerged due to the floods. 

The Observatory issued the first Red rainstorm warning signal of the year that day, which remained in effect for nearly seven hours.

Speaking on a radio program on Monday, Leung said the rainstorm warning system is designed to provide a general assessment of the overall weather conditions across Hong Kong but not specific districts. 

The former HKO assistant director added that the system also considers factors such as rainfall intensity, duration, coverage and its impact on different regions. 

In its "Weather Notes" published yesterday, the Observatory acknowledged that extreme weather conditions, including torrential rain, are becoming increasingly frequent due to climate change. 

It will continue to enhance the dissemination of weather information to update the public.