Japan: Adverse weather forecast across Tohoku and Hokuriku regions through at least July 20 /update 1

Event

Severe weather is forecast across Tohoku and Hokuriku regions through at least July 20. The Japan Meteorological Agency (JMA) has issued a warning regarding heavy rainfall, thunderstorms, and strong wind gusts across Tohoku Region July 18-19 and Hokuriku July 19-20 due to an approaching weather front. Rainfall totals of around 12 cm (5 inches) are expected in Tohoku and 10 cm (4 inches) in Hokuriku July 18-19, and totals of around 5-10 cm (2-4 inches) are expected across the affected region July 19-20. Storms may be accompanied by strong wind gusts, lightning, hail, and possible tornadoes. 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 18, the JMA has issued the following weather warnings across Tohoku Region;

• Purple heavy rain and landslide warnings (the second highest level on a four-tier scale): Parts of Iwate Prefecture.

• Red heavy rain and landslide warnings: Akita Prefecture.

• Red flood warnings: Parts of Iwate Prefecture.

• Yellow heavy rain and inundation warnings: Parts of Akita and Iwate prefectures.

• Yellow heavy rain and landslide warnings: Parts of Iwate and Yamagata prefectures.

• Yellow flood warnings: Parts of Akita Prefecture.

• Yellow thunderstorm warnings: Across the region with the exception of Aomori Prefecture.

• Yellow dense fog warnings: Parts of Aomori and Iwate prefectures.

No warnings have been issued for Hokuriku Region as of July 18. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions develop over the coming days.

Disruptions are ongoing across parts of Tohuku Region due to severe weather in recent days, predominantly across parts of Akita Prefecture. The heavy downpours have caused many rivers to reach dangerous levels, and landslides and flooding have caused widespread transportation disruptions in affected areas. Authorities are maintaining evacuation orders for more than 100,000 people across Akita, Daisen, and Noshiro cities and Gojome Town. The Babame and Uchikawa rivers overflowed and flooded Gojome Town July 15; one person died due to heavy rain, more than 500 houses are flooded, and almost all of the town is without water. Flooding has also damaged more than 200 houses in other parts of Akita Prefecture, including Akita and Noshiro cities and Mitane Town. Four people in Akita City suffered minor injuries due to a landslide. Water supply has been cut to more than 8,500 people across the prefecture, and nearly 5,000 people are without power as of July 18. Japan Railway East's Akita branch has announced that the Akita Shinkansen line will be closed between Morioka Station and Akita Station all day July 19. Evacuation orders have also been ordered for nearly 20,000 people in Kitakami City in Iwate Prefecture.

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 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.

Resources

Japan Meteorological Agency