Japan: Adverse weather forecast across western regions through at least Oct. 23

Severe weather is forecast across parts of western Japan through at least Oct. 23. The Japan Meteorological Agency (JMA) has issued a weather bulletin warning of heavy rainfall and thunderstorms across parts of the country through Oct. 23 due to a low-pressure system and the unstable weather has generated a linear rain band across Miyazaki Prefecture Oct. 22. Strong wind gusts, lightning, hail, and tornadoes may accompany storms.

As of Oct. 22, the JMA has issued the following weather warnings across the affected area:

• Purple heavy rainfall and landslide warnings (the second highest level on a four-tier scale): Parts of Miyazaki and Kagoshima prefectures.

• Red heavy rainfall, landslide, and flood warnings: Parts of Miyazaki and Kagoshima prefectures.

• Yellow heavy rainfall, landslide, and flood warnings: Parts of Kagoshima, Miyazaki, Oita, and Kochi prefectures.

• Yellow strong wind warnings: Across much of Northern Kyushu and Shikoku regions and parts of Chugoku and Kinki regions.

• Yellow high wave warnings: Some coastal areas of Kinki, Shikoku, and Northern and Southern Kyushu regions.

• Yellow storm surge warnings: Some coastal areas of Hyogo, Kyoto, and Shimane prefectures.

• Yellow thunderstorm warnings: Across the affected area.

Officials will likely issue new alerts or update/rescind existing advisories as weather conditions develop over the coming days.

Rainfall amounts of up to 12 cm (4.7 inches) in an hour have been recorded in parts of Miyzaki Prefecture Oct. 22, prompting officials to issue warnings for rivers reaching dangerous levels. Authorities in Miyazaki Prefecture have issued purple evacuation orders (the second highest level on a five-tier scale for evacuation warnings) for Hyuga, Kushima, Miyazaki, and Nichinan cities and Kawaminami and Tsuno towns due to the threat of flooding and landslides. Red evacuation of the elderly and vulnerable group warnings are also in place in Nobeoka City and Kadokawa 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.