19 Sep 2023 | 08:09 AM UTC
Japan: Adverse weather forecast across northern and eastern regions through at least Sept. 20
Severe weather forecast across northern and eastern Japan through Sept. 20. Flooding, landslides, and associated disruptions likely.
Event
Severe weather is forecast across parts of northern and eastern Japan through at least Sept. 20. As of Sept. 19, the Japan Meteorological Agency (JMA) issued a severe weather bulletin warning of heavy rainfall and thunderstorms across northern and eastern Japan due to a low pressure system. Strong wind gusts, lightning, hail, and possible tornadoes may accompany storms. Rainfall totals of around 8 cm (3.1 inches) in Hokkaido Prefecture and Tohoku Region and 6 cm (2.4 inches) in Hokuriku Region are expected late Sept. 19-20. Heavy downpours could trigger flooding in low-lying areas and landslides on unstable slopes. Strong winds may cause property damage and power outages.
As of Sept. 19, the JMA has issued the following weather warnings across the affected area:
Purple heavy rain/landslide warning (the second highest level on a four-tier scale): Parts of Akita Prefecture in Tohoku Region.
Red heavy rain/inundation warnings: Across Akita and parts of Fukushima prefectures in Tohoku Region.
Red heavy rain/landslide warnings: Parts of Akita Prefecture in Tohoku Region.
Red flood warnings: Across Akita Prefecture in Tohoku Region.
Yellow heavy rain/inundation warning: Soya Region in Hokkaido Prefecture.
Yellow heavy rain/landslide warnings: Parts of Aomori and Fukushima prefectures in Tohoku Region.
Yellow flood warnings: Parts of Aomori, Fukushima, and Iwate prefectures in Tohoku Region.
Yellow storm/gale warnings: Ishikari, Kushiro, Mombetsu, Rumoi, Shiribeshi, and Soya regions in Hokkaido Prefecture.
Yellow high wave warnings: Ishikari, Rumoi, Shiribeshi, and Soya regions in Hokkaido Prefecture.
Yellow storm surge warnings: Nemuro Region in Hokkaido Prefecture and parts of Aomori, Fukushima, and Iwate prefectures in Tohoku Region.
Yellow thunderstorm warnings: Across Hokkaido Prefecture, Tohoku Region, and Hokuriku Region.
Yellow dense fog warnings: Hidaka, Hiyama, Iburi, Ishikari, Kushiro, Nemuro, Oshima, Shiribeshi, Sorachi, Soya, and Tockahi regions in Hokkaido Prefecture and Aomori Prefecture in Tohoku Region.
Officials will likely issue new alerts or update/rescind existing advisories as weather conditions develop over the coming days.
As of Sept. 19, authorities have issued red evacuation orders (the fourth highest level on a five-tier scale) across Akita City in Akita Prefecture due to the risks of landslides and heavy rainfall. People in the city are advised to evacuate from at-risk areas. Around 11 cm (4.3 inches) of rainfall was recorded in western parts of Akita 14:00-15:00.
Sustained heavy rainfall will likely trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also probable in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are likely in hilly or mountainous areas, especially where heavy rainfall has saturated the soil.
Authorities could issue additional evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are likely where significant flooding or landslides impact utility networks.
Floodwaters and debris flows will likely render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.
Severe weather could also trigger flight delays and cancellations at airports in the affected areas. Flooding could 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 will likely occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, evacuations, and some employees' inability to reach work sites.
Advice
Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.
