The amber signal were the first stage of the warning system based on forecast of heavy rainstorms, and were used to alert government departments and major public transport and utility services. The red and black signals were the second stage of the warning system based on actual rainfall levels recorded, and were issued to the public.
The amber signal was the initial stage of the warning system, which was based on forecasts of heavy rainstorms, and was used to alert government agencies and major public services like transportation and utilities. The red and black signals were the second stage of the warning system, which was based on actual rainfall levels recorded, and were issued to the general public.