Japan: Adverse weather forecast across the Ryukyu Islands through at least June 13

Severe weather is forecast across the Ryukyu Islands through at least June 13. As of June 12, the Japan Meteorological Agency (JMA) has issued the following weather warnings:

• Purple landslide warnings (the highest level on a three-tier scale): Amami region in Kagoshima Prefecture.

• Red heavy rain, landslide, and flood warnings: Okinawa main island in Okinawa Prefecture.

• Yellow warnings: Across 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. The severe weather is forecast to persist through at least June 13.

As of June 11, authorities have issued purple evacuation warnings (the second highest level on a five-tier scale for evacuation warnings) for more than 2,500 people in Tomigusuku City, Okinawa Prefecture, and more than 600 people in Setouchi Town, Kagoshima Prefecture. Red evacuation warnings for elderly people and other vulnerable groups are in place for parts of Nanjo, Itoman, and Nago cities, Nishihara Town, Ogimi Village in Okinawa Prefecture, and Uken Village in Kagoshima Prefecture. Reports indicate that a building in Tamemata, Nago City, Okinawa Prefecture, was damaged early June 12; there are no reports of casualties.

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.