Key Facts
• Active convective activity observed in southern seas near Japan.
• Simulations predict counterclockwise circulations from September 16 (Tue) to 25 (Thu).
• Potential development into tropical depressions or typhoons remains uncertain.
• Counterclockwise circulation expected in South China Sea (Sep 16–18), no impact on Japan.
• New circulation near the Philippines (Sep 19), unlikely to develop further.
• Circulation west of Guam and Saipan (Sep 23) shows signs of intensification and northward movement.
• Autumn rain front to lower temperatures in northern and eastern Japan later this week.
• Western Japan and Kyushu to experience lingering summer heat.
• Weekly forecasts for five cities per prefecture available via images.
• Meteorological Agency updates critical for tracking potential typhoon development.
Summary
The southern seas near Japan are experiencing heightened convective activity, with simulations indicating counterclockwise circulations that could develop into tropical depressions or typhoons. While a circulation in the South China Sea (Sep 16–18) poses no threat to Japan, another near the Philippines (Sep 19) is expected to remain stationary without significant development. A third circulation west of Guam and Saipan (Sep 23) shows potential for intensification and northward movement, warranting close monitoring. Meanwhile, the autumn rain front will bring cooler temperatures to northern and eastern Japan, while western regions and Kyushu will continue to experience residual summer heat. Weekly forecasts for cities across Japan are available, and updates from the Meteorological Agency are crucial for tracking these weather patterns.
