August 30, 2025
TAIPEI – Despite the presence of a high-altitude cold-core low pressure system over Taiwan on Friday (August 29), the expected afternoon convective weather was weaker than anticipated due to limited moisture in the atmosphere, according to weather analyst Wu Shengyu.
Wu explained through his “Weather Expert – Wu Shengyu” Facebook page that while atmospheric instability was high, the lack of sufficient water vapor restricted the intensity of thermal convection. The cold-core low has since shifted north toward Zhejiang Province and will continue to move away from Taiwan through the weekend.
With the system’s departure, winds at low and mid-levels are forecast to gradually shift to a southeast-to-southerly flow, allowing more moisture to enter Taiwan. Wu noted that brief showers are possible in windward areas, particularly from southern Hualien and Taitung down to the Hengchun Peninsula. In the afternoons, local thunderstorms remain a concern, especially across mountainous regions and nearby plains in western Taiwan. Isolated severe thunderstorms cannot be ruled out.
Heatwave Continues
Wu also cautioned that high temperatures persist across the island. Some areas could see daytime highs between 36 and 38 degrees Celsius. He advised the public to take precautions against sun exposure and heat-related illnesses.
As September approaches, summer-like conditions are expected to linger. Wu said the Pacific high pressure system is forecast to gradually retreat eastward, shifting Taiwan’s prevailing winds to the southeast and south. This may lead to stronger convection and a wider coverage of rainfall in the afternoons. While occasional rainfall could cause slight drops in temperature, many areas will still experience highs of 34–36°C, with isolated locations topping 36°C.
Typhoon Blue Lake No Threat to Taiwan
Meanwhile, Tropical Depression TD-17 developed into Typhoon Blue Lake on Saturday morning (August 30) south of Hainan Island. Wu stated that the storm will make landfall in Vietnam later today or tomorrow before weakening over the Indochina Peninsula. He stressed that it poses no threat to Taiwan.
Looking ahead, Wu noted that as the Pacific high shifts east, the monsoon trough will also lift northward. A new tropical disturbance could form in waters east of Taiwan and south of Japan next week, likely tracking north toward Japan. However, the broader monsoon trough may remain active into mid-September, bringing further disturbances to monitor.
Autumn Still Some Weeks Away
Wu pointed out that while weather systems are beginning to shift northward, their distance from Taiwan, combined with the Pacific high’s influence, makes it unlikely they will affect the island in the first half of September. A more noticeable transition toward autumn-like weather may not occur until late September.
Wu emphasized that his insights are intended for academic reference, and official forecasts should be based on updates from the Central Weather Administration.
