The Hong Kong Observatory (HKO) issued the Standby Signal, No. 1, on Monday afternoon as Typhoon Fung-wong moved within the 800-kilometer monitoring range of the territory. While expected to pass at a significant distance, meteorologists caution that the interaction between the tropical cyclone and a prevailing dry monsoon could heighten wind risk, potentially escalating storm signals mid-week.
The HKO’s Acting Senior Scientific Officer, Lui Yuk-sing, confirmed that the signal was slated for 12:20 p.m. Fung-wong is forecast to chart a path approximately 400 kilometers or more to the east of Hong Kong between Tuesday night and early Wednesday morning, representing its closest approach. Residents are urged to monitor official updates closely.
Monsoon Influence Modifies Storm Outlook
The current weather dynamics are unusually complex, being governed by two competing forces: the approaching tropical storm and a persistent dry northeast monsoon dominating southern China. Lui noted that as Fung-wong tracks into the northeastern South China Sea, this cooler, drier airstream is likely to weaken its intensity.
Currently, initial wind conditions in Hong Kong are not projected to be severe due to prevailing northerly winds and the topographical shielding effect. However, the decision to raise higher tropical cyclone signals hinges on three critical variables: any unexpected shift in Fung-wong’s strength, its timing of recurvature (or change in direction), and its ultimate proximity to the city.
The HKO predicts that strong force 6 winds are likely later on Tuesday, potentially reaching gale force 8 in high-ground areas early Wednesday. If the city falls within the storm’s strong wind field, the Strong Wind Signal, No. 3, remains a distinct possibility.
The Dynamics of Dual Weather Systems
Leung Wing-mo, a spokesperson for the Hong Kong Meteorological Society, explained how the interplay between the monsoon and the cyclone will dictate local conditions. In classical meteorology, determining the dominant weather driver relies on analyzing the pattern of isobars (lines of equal pressure).
As of Monday morning, the monsoon remained in charge, as the tropical cyclone’s outer circulation had not yet completely encompassed Hong Kong. However, as Fung-wong tracks northwards, its outer isobars may interact with the territory, transitioning conditions toward storm-led influences.
Leung emphasized that the actual wind speed matters more than the nominal dominance of either system. Autumn typhoon winds frequently arise from the combined pressure gradient squeezed between the monsoonal ridge (high pressure) and the cyclone’s low pressure. This tightening of isobars effectively enhances wind speeds. Paradoxically, the same dry, cool continental air that boosts this wind gradient can also disrupt the tropical storm’s structure and alter its predicted path, making strength forecasting inherently challenging.
Preparation and Seasonal Context
Based on current forecasts, only minor coastal flooding is possible in some low-lying shoreline areas from Monday night into early Tuesday, with rainfall limited to brief, sporadic showers. The combined effect of the monsoon and the cyclone is expected to draw cooler air into the region, potentially dropping mid-week temperatures to around 20°C.
While strong November typhoons are infrequent but not unprecedented—Super Typhoon Yinxing, Typhoon Toraji, and Typhoon Man-yi occurred around this time in previous years—Leung suggested that the local typhoon season is likely nearing its end after Fung-wong. The typical cooling of the South China Sea in late autumn usually hinders the formation and maintenance of robust cyclones.
However, Leung cautioned that climate change-related factors, such as elevated sea temperatures, could extend the season into December, citing the example of Super Typhoon Rai in 2021. The public is strongly advised to maintain close vigilance and adhere to updates provided by the Hong Kong Observatory throughout the week.