The Amber Rainstorm Warning Signal is now in effect. The Hong Kong Observatory (HKO) stated that rain is particularly heavy in Yuen Long District and Tsuen Wan District which may cause serious flooding. In particular, severe rainstorm is affecting Yuen Long District with more than 100 millimetres of hourly rainfall fallen or expected to fall; heavy rain is affecting Tsuen Wan District with more than 70 millimetres of hourly rainfall fallen or expected to fall.