Japan will experience episodic heavy rainfall events

Affected by both an upper-level trough and a subtropical high-pressure system (Figure 1), Japan will experience episodic heavy rainfall events. From June 8 to 11, the central and southern regions of Japan will see heavy to torrential rain. Specifically, the central region, Kinki region, western Shikoku Island, and most of Kyushu Island are forecasted to experience extremely heavy rain, with cumulative rainfall amounts ranging from 100 to 230 millimeters (Figure 2). These areas will also be accompanied by severe convective weather, including short-duration intense rain and thunderstorms with strong winds.

Figure 1. Average Geopotential Height at 500 hPa (Contour Lines, Units: dagpm) and Wind Field at 850 hPa (Wind Barbs, Units: m/s) from June 8 to 11, 2025

Figure 2. Accumulated Precipitation from June 8 to 11, 2025 (Shaded, Unit: mm)

Author: Huo Da                                 Reviewer: Niu Ruoyun 

English reviewer:Wang Yi                                                                       Issue approver:Dai Kan