Japan: Adverse weather forecast across most of the country through at least July 26

Severe weather is forecast across most of Japan through at least July 26. As of early July 25, the Japan Meteorological Agency (JMA) has warned of possible landslides and flooding across eastern and northern Japan and possible lightning, tornadoes, strong wind, and hail across western and northern Japan July 26. Forecast models indicate rainfall of 15 cm (6 inches) across the Tohoku region, 8 cm (3 inches) in the Hokuriku region, and 6 cm (2 inches) in the Kanto and Koshin regions through early July 26. The JMA has issued the following weather warnings across the affected area:

• Purple landslide warnings (the highest level on a three-tier scale): Akita and northern Yamagata prefectures.

• Red heavy rain, flood, and landslide warnings: western Iwate and northern Niigata prefectures.

• Yellow warnings: Across most of the rest of Japan.

Officials will likely issue new alerts or update/rescind existing advisories as weather conditions develop over the coming days.

Authorities have issued evacuation orders for tens of thousands of residents in Daisen, Nikaho Yokote, and Yurihonjo cities and Misato Town in Akita Prefecture, Sakata and Tsuruoka cities, and Kanayama, Mamurogawa, and Yuza towns in Yamagata Prefecture. Evacuation orders for the elderly and vulnerable are in place for parts of Yuzawa City in Akita Prefecture.

A landslide occurred near National Route 13 in Yuzawa City, Akita Prefecture early July 25; one person remains missing. A levee near the Ayuse Observatory on the Ishizawa River in Yurihonjo City collapsed, flooding 10 houses. Seven buildings in Nikaho City and 18 houses in Yokote City have also been flooded. Authorities have suspended some local train services in northern Japan due to heavy rainfall and flooding.

Sustained heavy rainfall could trigger further flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil. Disruptions to electricity and telecommunications services are likely where significant flooding, landslides, or strong winds impact utility networks.

Floodwaters and debris flows will likely render some bridges, rail networks, or roadways impassable, impacting overland travel around affected areas. Ponding on road surfaces will probably cause hazardous driving conditions on regional highways. Authorities will likely temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather will also probably cause intermittent flight delays and cancellations at airports across the affected region, though these are unlikely to be severe or prolonged. Authorities will likely suspend port operations or close beach fronts temporarily if strong winds trigger hazardous sea conditions. Flooding will probably block regional rail lines; freight and passenger train delays and cancellations are likely in areas with heavy rainfall and potential track inundation. Localized business disruptions are probable in low-lying areas.