Japan: Severe weather ongoing in southern and central regions as of Aug. 16 /update 3

Event

Heavy rains are ongoing in southern, western, and central areas of Japan as of Aug. 16. The Japan Meteorological Administration has issued the following warnings:

• Purple (the second-highest level on a four-tier scale) warnings for landslides due to heavy rain: Western Kagoshima, western and central Kumamoto, southern Nagasaki, and eastern Saga prefectures.

• Red warnings for heavy rainfall, flooding, and landslides: Western Aichi, western Ehime, Fukuoka, Hiroshima, western Kanagawa, the rest of Kagoshima, the rest of Kumamoto, western Miyazaki, Nagano, the rest of Nagasaki, northern Oita, and the rest of Saga prefectures.

• Yellow heavy rain, thunderstorms, flooding, and landslide advisories: The rest of the affected area.

Officials forecast the adverse weather will continue in the coming days; government officials may expand evacuation orders in the coming days if weather conditions persist or worsen.

Through late Aug. 17, the low-pressure system is likely to bring at least 25 cm (10 inches) of rainfall to Kyushu as well as the Shikoku region, 20 cm (8 inches) of rainfall to the Chugoku Region, 12 cm (4.5 inches) of rainfall to the Kinki and Tokai regions. The Shikoku and Tokai regions are forecast to have 20-30 cm (8-12 inches) of rainfall from late Aug. 17 to late Aug. 18.

Authorities have ordered nearly 1.5 million people to evacuate from Fukuoka, Hiroshima, Hyogo, Kumamoto, Nagasaki, Nagano, Niigata, Oita, Osaka, Saga, and Yamaguchi prefectures.

Several rivers have overflowed in worst-hit regions. At least four people have been killed, including three people who were killed in a landslide in Okaya City, Nagano Prefecture, and one person who was killed by a landslide in Unzen City, Nagasaki Prefecture. At least 18 people have also been injured. At least three buildings have been destroyed and six buildings damaged, with at least 4,119 buildings flooded. Officials will likely provide updates on casualties and damages in the coming days.

Hazardous Conditions
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 are 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.

Transport
Multiple railways and train lines in affected areas have experienced disruptions, with trains suspended or delayed due to heavy rain. 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 regional airports. Authorities may temporarily suspend port operations or close beach fronts along the Philippine Sea, East China Sea, and the Sea of Japan 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.

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 Administration