Thunderstorms and heavy rains bringing possible floods, landslides, and lightning are forecast across northern Japan through at least Aug. 4. As of early Aug. 3, the Japan Meteorological Administration has issued the following warnings:
- Purple (highest level on a three-tier scale) warnings for heavy rain and landslides: Akita, Aomori, and Iwate prefectures.
- Red heavy rain and flood warnings: western Yamagata Prefecture.
- Yellow heavy rain, thunderstorms, flooding, gale, and landslide advisories: the rest of the affected area.
Authorities will likely issue new warnings or update existing advisories in the coming days
Forecast models indicate 24-hour rainfall totals of 18 cm (7 inches) in the Tohoku region through early Aug. 4. Authorities have warned of possible flooding of rivers in Aomori Prefecture, including the Kanita River through Sotogahama Town, the Oirase River through Towada City, Shimouchi River through Odate City, and the Iwaki River.
Authorities have issued evacuation orders for residents in landslide-prone areas of Akita, Aomori, and Iwate prefectures; officials may issue additional evacuation orders if weather conditions persist or worsen.
JR East suspended the Akita Shinkansen between Akita and Morioka stations early Aug. 3 due to heavy rain in the Tohoku region; authorities estimate that services will be suspended through at least 15:00 Aug. 3. Authorities have also warned that the Yamagata Shinkansen is likely to be delayed or canceled between Yamagata and Shinjo stations 12:00-18:00 Aug. 3 due to hazardous conditions. Authorities have suspended multiple other local train services in northern Japan due to the adverse weather conditions. The Tohoku Expressway in Aomori Prefecture was closed early Aug. 3 between the Owani Hirosaki and the Ikarigaseki interchanges due to heavy rain. Portions of National Route 280 and 338 as well as Prefectural Route 14 are also closed due to landslides. A landslide on National Route 103 in Lake Towada, Kosaka Town, Akita Prefecture early Aug. 3 trapped at least three cars; there are no reports of injuries.
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 located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides remain possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.
Floodwaters and debris flows may 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 region.
Authorities may temporarily suspend port operations or close beach fronts if strong winds trigger hazardous sea conditions. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track inundation.
Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees’ inability to reach work sites.
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.