Japan: Adverse weather forecast across most of country until at least Dec. 7

Severe weather is forecast across most of Japan until at least Dec. 7. As of early Dec. 6, the Japan Meteorological Agency (JMA) has issued the following weather warnings across the affected areas:

• Red storm warnings (the middle level on a three-tier scale): Western Akita and western Yamagata prefectures.

• Red heavy rain and landslide warnings: Northern and central Niigata Prefecture.

• Red high wave warnings: Ishikawa and northern and central 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.

Sustained heavy rainfall could trigger 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 possible where significant flooding, landslides, or strong winds impact utility networks.

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

Severe weather may cause intermittent flight delays and cancellations at airports across the affected regions, though these are unlikely to be severe or prolonged. Authorities could suspend port operations or close beachfronts temporarily if strong winds trigger hazardous sea conditions. Flooding may block regional rail lines; freight and passenger train delays and cancellations are possible in areas that experience heavy rainfall and track inundation. Localized business disruptions are possible in low-lying areas.