Indonesia weather alerts issued as tropical cyclone seed detected

The Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) has issued various weather warnings across the archipelago for mid-September 2026. A tropical cyclone seed, designated 98W, has been detected in the South China Sea east of Vietnam. While it has a low probability of developing into a full cyclone within 24 hours, its presence is creating atmospheric convergence and low-level jets stretching from the Gulf of Thailand to the South China Sea.

Significant weather patterns include warnings for heavy to very heavy rain in Aceh and North Sumatra. Other regions, such as West Sumatra, are expected to experience thunderstorms and rain through the weekend. In western Indonesia, areas like Padang face potential thunderstorms, while Medan may see moderate rain.

In the Jabodetabek area, conditions are expected to be mostly cloudy to partly cloudy, though Tangerang has been advised to watch for increased wind speeds. In Yogyakarta, residents should be aware of potential fog or haze in Kulon Progo and hazy conditions in Bantul. Eastern Indonesia is also expected to see light rain in several provinces, including Papua and Manokwari.