Japan: Adverse weather forecast across most of the country through at least July 4

Severe weather is forecast across most of Japan through at least July 4. As of early July 1, the Japan Meteorological Agency (JMA) has warned of possible landslides and flooding across northern Japan July 1 and across western and eastern Japan from July 2. Forecast models indicate rainfall of 20 cm (8 inches) across the northern Kyushu region, 15 cm (6 inches) in the Tokai, Kinki, and Chugoku regions, and 10 cm (4 inches) in the Hokuriku and Shikoku regions July 1. Rainfall of 10 cm (4 inches) is likely in the Chugoku region July 2 and 12 cm (5 inches) over the Hokuriku region July 3. Less rainfall is forecast for the rest of Japan through early July 4.

The JMA has issued the following weather warnings across the affected area:

• Purple landslide warnings (the highest level on a three-tier scale): Fukuoka, central Nagano, northern and western Oita, southern Saga, western and central Shimane, eastern and central Toyama, and most of Yamaguchi prefectures.

• Red heavy rain, flood, and landslide warnings: most of the rest of Kyushu and western Honshu regions.

• 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 parts of Fukuoka, Hiroshima, Hyogo, Nara, Oita, Shimane, Toyama, Wakayama, and Yamaguchi prefectures. Evacuation orders for the elderly and vulnerable are in place for parts of Kumamoto and Saga prefectures. Some trains on the Sanyo Shinkansen are delayed due to the heavy rainfall. Japan Railway (JR) suspended all conventional lines in Hiroshima Prefecture early July 1; some services have since resumed. Tokyo Bay Ferry connecting Kanaya Port in Futtsu City, Chiba Prefecture, with Kurihama Port in Yokosuka City, Kanagawa Prefecture, suspended operations early July 1 due to strong winds.

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 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.