The Meteorological and Geophysical Bureau (SMG) said on its website yesterday that it will hoist tropical cyclone Standby Signal No.1 this morning as a tropical depression, which formed in the South China Sea a bit over 800 kilometres from Macau yesterday morning, was slated to remain about 800 kilometres from Macau early today and expected to gradually strengthen and move towards Hainan Island over the next one or two days.
Depending on its location and strength, Macau’s observatory classifies a tropical cyclone into tropical depression, tropical storm, strong tropical storm, typhoon, strong typhoon, and super typhoon.
Signal No.1 is the lowest of Macau’s tropical cyclone warning signals. It is hoisted when a tropical cyclone comes within 800 kilometres from Macau. Its higher warning typhoon signals are the No.3, No.8, No.9, and No.10.
The SMG website says that Signal No.1 is a “precautionary” signal indicating that the centre of a tropical cyclone is within 800 kilometres from Macau and it is forecast to affect the special administrative region.
The bureau said yesterday that a low-pressure area located in the central South China Sea evolved into a tropical depression yesterday morning. However, the bureau said, the tropical cyclone, which formed at a location a bit over 800 kilometres from Macau, was moving slowly and was forecast to remain about 800 kilometres from Macau early today.
The bureau underlined yesterday that based on its forecast for the tropical cyclone’s possible trajectory, it will hoist the Standby Signal No.1 “at an appropriate time” this morning.
The bureau said that the tropical depression is forecast to gradually become stronger and move towards the vicinity of Hainan Province over the next one or two days, after which it is forecast to turn towards the western coast of Guangdong Province.
The bureau’s website said that the circulation associated with the tropical depression was expected to bring unstable weather to the coast of Guangdong later this week, when winds in Macau are expected to intensify, accompanied by frequent showers and thunderstorms.
2 factors determining impact on Macau
The bureau said in a follow-up statement yesterday that the tropical cyclone was forecast to continue moving slowly towards the vicinity of Hainan Province over the next two days, after which it was forecast to undergo a change in its moving direction by the end of this week, approaching the western coast of Guangdong Province.
The statement said that two main factors will determine whether the expected change in the tropical cyclone’s direction will have a stronger impact on Macau.
According to the statement, the first factor is whether the tropical cyclone will first make landfall on Hainan Province before changing direction. If yes, the statement said, its strength would weaken.
The second factor is whether the tropical cyclone, after making a change in direction, will adopt a more northeasterly trajectory, approaching an area within 300 kilometres west of the Pearl River Estuary, in which case Macau would be more significantly affected by the tropical cyclone, the statement said.
The statement also said that as Macau will be affected by an astronomical high tide by the end of this week, low lying areas in the Inner Harbour district would be affected by minor flooding caused by a storm surge if the tropical cyclone moves closer to the Pearl River Estuary.
Meanwhile, the Hong Kong Observatory issued the Standby Signal No. 1 at 12:40 a.m. today.
Image Source SMG
