Japan: Adverse weather forecast across the Ryukyu Islands through at least June 16

Severe weather is forecast across the Ryukyu Islands through at least June 16. Heavy rainfall has been ongoing in the region in recent days, leading to flooding and an increased threat of landslides across the region. Further rainfall is forecast over the coming days, which will likely exacerbate the situation; rainfall totals of around 12 cm (5 inches) are forecast in the Amami Islands and around 10 cm (4 inches) in Okinawa Prefecture June 14-15. Authorities have issued purple evacuation warnings (the second highest level on a five-tier scale for evacuation warnings) across Tomigusuku, Nanjo, Itoman, Naha, Urasoe, and Ginowan cities, Nishihara, Haebaru, Yonabaru, Chatan, and Yaese towns, and Kitanakagusuku and Nakagusuku villages in Okinawa due to the increased landslide threat, affecting hundreds of thousands of people. Red evacuation of vulnerable group warnings are in place for Nago, Okinawa, and Uruma cities and Ogimi Village. Officials will likely update. expand, or rescind the status of evacuation orders as weather conditions change over the coming hours and days.

As of June 14, the Japan Meteorological Agency (JMA) has issued the following weather warnings across the affected area:

• Purple heavy rain/landslide warnings (the highest level on a three-tier scale): Across Okinawa main island.

• Red heavy rain and flood warnings: Across central and southern Okinawa main island.

• Yellow heavy rain, landslide, and flood warnings: Northern Okinawa main island, Kumejima, and the Amami Islands.

• Yellow thunderstorm warnings: Across the affected area.

• Yellow high wave warnings: Across central and southern Okinawa main island and the Sakishima Islands.

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 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.