The Hong Kong Observatory rolled out a localised weather warning system, named “Announcement on Localised Heavy Rain,” on Friday. A local rainstorm warning system will be signalled if rainfall reaches red or black rainstorm warning criteria.

Red and black rainstorm warning signals are raised when rainfall has exceeded 50 millimetres and 70 millimetres respectively, and is likely to continue.

“MyObservatory” app. Photo: Hong Kong Observatory.

The warning system will indicate the affected areas and amount of rainfall through radio, television and the Observatory website, as well as the “MyObservatory” smartphone application, according to a press release published on Thursday. The Observatory said that the system was to “alert the public of potential flooding due to heavy rain in the districts, so as to take precautionary measures.”

The existing system for the northern New Territories, “Special Announcement on Flooding in the northern New Territories,” will still be in place, while the localised heavy rain system will be used for all other areas.

Waterloo Road under heavy rain on April 13.

Controversy erupted on April 13 when torrential rain hit the city, causing floods and chaos. At that time, several districts exceeded 50 millimetres of rainfall per hour, but only an amber signal was raised. The Observatory later said that as most districts fit the amber rainstorm criteria, and that the rainband would soon leave Hong Kong, they judged that there was no need to raise the red rainstorm warning.

Chantal Yuen

Chantal Yuen is a Hong Kong journalist interested in issues dealing with religion and immigration. She majored in German and minored in Middle Eastern studies at Princeton University.