Heavy Rainfall Expected in the Korean Peninsula, Japan, and Other Regions

Over the past 3 days, parts of the Korean Peninsula, central and southern Japan, and southern Russian Far East have experienced heavy rain or torrential rain, with localized areas witnessing downpours. Accumulated precipitation reached 50 to 120 mm, with some southern parts of South Korea exceeding 150 mm (Figure 1).

Over the next week, under the combined influence of a low vortex and monsoon systems (Figure 2), frequent rainfall is forecast across the aforementioned regions. Parts of North Korea, South Korea, most of Japan, and the Russian Far East will see heavy to torrential rain, with localized downpours, accompanied by severe convective weather including short-duration intense rainfall and thunderstorms with strong winds. The accumulated precipitation in these areas is expected to range from 40 to 90 mm, with 100 to 200 mm in some regions, and locally over 300 mm in southern Japan (Figure 3).

Attention should be given to the potential secondary disasters triggered by the heavy rainfall in the aforementioned areas, including flooding, landslides, mudslides, and urban waterlogging.

Figure 1 Accumulated Precipitation from August 2 to 4, 2025 (Unit: mm)

Figure 2 500 hPa Geopotential Height (Contour Lines) and 850 hPa Wind Field (Wind Barbs) at 12:00 UTC, August 6, 2025

Figure 3 Forecasted Accumulated Precipitation from August 6 to 12, 2025 (Unit: mm)

Author: Li Ming                                 Reviewer: Guan Yue 

English reviewer:Wang Yi                                                                       Issue approver:Dai Kan