Japan: Adverse weather forecast across northern and eastern regions through at least Sept. 3

Severe weather is forecast across parts of northern and eastern Japan through at least Sept. 3. The Japan Meteorological Agency (JMA) has issued a weather bulletin warning of rainfall totals of around 10 cm (4 inches) across the Tokai and Kanto regions and 8 cm (3 inches) in the Tohoku Region through the evening of Sept. 3. People in the affected areas are advised to be on alert for flooding and landslides. Strong wind gusts, lightning, hail, and tornadoes may accompany storms.

As of Sept. 3, the JMA has issued purple (highest level on a three-tier scale) landslide warnings across southern Chiba Prefecture and red heavy rain and landslide warnings across the rest of Chiba Prefecture. Yellow thunderstorm and flood advisories are in place across most of the rest of the affected area. Officials will likely issue new alerts or update/rescind existing advisories as weather conditions develop over the coming days.

Authorities in Chiba Prefecture have issued purple evacuation orders (the second highest level on a five-tier scale for evacuation warnings) for Ichihara, Kamogawa, Minamiboso, and Tateyama cities and red evacuation of the elderly and vulnerable group warnings for Tako Town. Officials will likely update, expand, or rescind the status of evacuation orders as weather conditions change over the coming hours and 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 likely where significant flooding, landslides, or strong winds impact utility networks.

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

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