13 Jul 2023 | 11:57 AM UTC
Japan: Adverse weather forecast to continue across much of the country through at least July 16 /update 3
Severe weather forecast to continue across much of Japan through at least July 16. Evacuations ongoing in multiple regions.
Event
Severe weather is forecast to continue across much of Japan through at least July 16. As of July 13, the Japan Meteorological Agency (JMA) has warned that a weather front will move slowly northward over the country over the coming days, stagnating over Tohoku region July 15. Heavy rainfall and thunderstorms are expected over western regions July 13, eastern regions July 14, and Tohoku Region July 15-16. Storms may be accompanied by strong wind gusts, lightning, hail, and possible tornadoes. Rainfall totals of around 15 cm (6 inches) are forecast in Hokuriku Region July 13-14, 10-20 cm (4-8 inches) in Tohoku and 5-10 cm (2-4 inches) in Hokiriku July 14-15, and 10-15 cm (4-6 inches) in Tohoku Region July 15-16. 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 July 13, the JMA has issued the following weather warnings across the country:
Purple heavy rain/landslide warnings (the second highest level on a three-tier scale): Parts of Niigata and Toyama prefectures in Hokuriku Region.
Red heavy rain/inundation warnings: Parts of Niigata Prefecture in Hokuriku Region and Kyoto Prefecture in Kinki Region.
Red heavy rain/landslide warnings: Parts of Soya Region in Hokkaido Prefecture; Gigu Prefecture in Tokai Region; Fukui, Ishikawa, and Toyama prefectures in Hokuriku Region; Hyogo, Kyoto, and Shiga prefectures in Kinki Region; and Tottori Prefecture in Chugoku Region.
Red flood warnings: Parts of Niigata Prefecture in Hokuriku Region and Kyoto Prefecture in Kinki Region.
Yellow heavy rain/inundation warnings: Parts of Kushuro and Hemuro in Hokkaido Prefecture; Nagano Prefecture in Kanto Koshin Region; Niigata Prefecture in Hokuriku Region; and Hyogo Prefecture in Kinki Region.
Yellow heavy rain/landslide warnings: Parts of Abashiri, Kamikawa, Kushiro, Mombetsu, Nemuro, and Rumoi regions in Hokkaido Prefecture; Nagano and Tochigi prefectures in Kanto Koshin Region; Gifu Prefecture in Tokai Region; Ishikawa and Niigata prefectures in Hokuriku Region; Hyogo and Kyoto prefectures in Kinki Region; Shimane Prefecture in Chuoku Region; and Fukuoka, Nagasaki, Oita, and Yamaguchi prefectures in Northern Kyushu Region.
Yellow flood warnings: Parts of Abashiri, Mombetsu, Nemuro, and Soya regions in Hokkaido Prefecture; Nagano Prefecture in Kanto Koshin Region; Fukui, Niigata, and Toyama prefectures in Hokuriku Region; Hyogo and Kyoto prefectures in Kinki Region; and Tottori Prefecture in Chugoku Region.
Yellow storm gale warnings: Kanagawa Prefecture in Kanto Koshin Region and parts of Fukuoka, Kumamoto, Nagasaki, Saga, and Yamaguchi prefectures in Northern Kyushu Region.
Yellow high wave warnings: Parts of Chiba and Kanagawa in Kanto Koshin Region and Nagasaki Prefecture in Northern Kyushu Region.
Yellow storm surge warnings: Parts of Hyogo and Kyoto prefectures in Kinki Region.
Yellow thunderstorm warnings: Across Tokai, Hokuriku, Kinki, Chugoku, and Shikoku regions; much of Hokkaido Prefecture, Kanto Koshin Region, and Northern Kyushu Regions; and Fukushima Prefecture in Tohoku Region.
Yellow dense fog warnings: Across much of Hokkaido Prefecture and the Izu Islands in Tokyo Prefecture, Kanto Koshin Region.
Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions develop over the coming days.
Disruptions are ongoing across multiple regions of Japan due to severe weather in recent days. Southwestern regions have been worst affected; authorities have reported at least seven fatalities and two others are missing in Fukuoka, Oita, and Saga prefectures in Northern Kyushu Region. Another fatality was reported in Toyama Prefecture in Hokuriku Region July 13. As of July 13, evacuation orders have been issued for more than 150,000 people across parts of Fukui Prefecture, more than 10,000 people in Fukuoka Prefecture, and more than 2,400 others across Tottori, Saga, Nagasaki, and Oita prefectures. The heavy downpours have caused many rivers to reach dangerous levels and landslides and flooding have caused widespread transportation disruptions in affected areas.
Hazardous Conditions
Further sustained heavy rainfall could trigger additional flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also likely 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.
Transport
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 that see 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.
