Unprecedented Rainfall and Storms Hit Japan and Western Europe

Mid-August brought an “unprecedented” deluge to Chiba, followed by extreme rain in Ishikawa and Toyama prefectures. In Himi, Toyama, 361.5 mm fell within 24 hours—about half the average annual rainfall of London and Paris. Japan’s Meteorological Agency issued its highest-level rain warning and landslide alerts, prompting the evacuation of hundreds of thousands of residents. Rivers burst their banks, causing flash floods and mudslides that damaged buildings. Forecast models indicated a further 200 mm of rain could fall just south of the region as moisture continued moving westward.

The Guardian

Two days earlier, Typhoon Saudel passed through Kagoshima and Okinawa, delivering winds of 100 mph (160 km/h) and 230 mm of rain in the Amami region in a single day. The storm was expected to weaken as it moved toward southeast China.

The Guardian

At the same time, western Europe experienced a series of severe convective storms, especially in the Alpine zones. Spain, France, and Italy reported intense rain, strong winds, large hail, and tornadoes. Hailstones up to 10 cm in diameter were documented in Catalonia, and a significant tornado struck the village of Pomas in southwestern France.

The Guardian

Scientists note that the developing El Niño this year may be amplifying these events. In El Niño years, the North Pacific ridge tends to shift northward, allowing weather fronts to penetrate Japan more easily and encouraging tropical storms to recurve toward the archipelago. This contrasts with La Niña patterns, where the semi-permanent North Pacific High often blocks such systems.

The Guardian

Japanese authorities have mobilized emergency services to rescue flood-stranded residents and reinforce riverbanks, while European civil-protection agencies are conducting damage assessments and issuing further weather warnings. The concurrent extreme weather underscores the broader challenges posed by shifting climate patterns and the need for coordinated preparedness across affected regions.

The Guardian