17th August 2026 – (Hong Kong) Hong Kong may again come under tropical-cyclone influence as the Observatory warns a broad low pressure trough could affect the northern South China Sea to waters east of Luzon — and may even split into two separate low-pressure areas.
The forecaster said development and track of any lows on the trough remain highly uncertain. The one over the northern South China Sea is expected to strengthen slightly and has a fair chance of moving toward Hainan Island over the next two to three days, a path that would keep the immediate threat to Hong Kong indirect for now but still worth watching.
Computer guidance on the Observatory’s Earth Weather platform paints a more dramatic picture. The Fengwu artificial-intelligence model suggests that from Wednesday 19th August to Sunday 23rd August two potential tropical cyclones could sit within 800 kilometres of Hong Kong at the same time — the so-called “twin spin dance”. Other AI systems, including the European Centre for Medium-Range Weather Forecasts’ AIFS model and China’s Fuxi model, likewise show two potential cyclones along southeastern China’s coast around the same period on Thursday. Those outputs are experimental and can shift sharply run to run; they do not replace the Observatory’s official track forecasts.
Officially, the low-pressure areas are only expected to develop gradually, and a tropical cyclone could form around the middle of this week if conditions align. That fits a nine-day outlook that turns noticeably rougher after Tuesday. Tomorrow, 18th August, should stay mostly cloudy with a few showers and thunderstorms, heavier in places at first and brief sunshine later. From Wednesday onwards the weather is due to deteriorate, with offshore and high ground seeing force 6 winds at times.