26 Apr 2022 | 10:09 AM UTC
Japan: Adverse weather forecast across much of the country through at least April 28
Severe weather forecast across much of Japan through at least April 28. Possible flooding and associated disruptions.
Event
Adverse weather is forecast across much of Japan through at least April 28. An active weather front will bring widespread heavy rainfall across Kyushu and much of Honshu islands April 27. The heavy downpours may be accompanied by thunderstorms, strong winds, lightning, and possible tornadoes. Authorities have warned of possible landslides and flooding triggered by the heavy rainfall. Rainfall totals of 10-25 cm (4-10 inches) are forecast across the affected area early April 27, with a further 5-10 cm (2-4 inches) expected in some areas April 27-28. In other parts of Japan, strong winds, melting snow, avalanches, and dense fog are forecast in Hokkaido Prefecture and thunderstorms are expected across parts of Okinawa Prefecture.
As of April 26, the Japan Meteorological Administration has issued the following warnings:
Red (the second-highest level on a three-tier scale) heavy rain (inundation) warnings: Shimane Prefecture in Chugoku Region and parts of Kumamoto Prefecture in Kyushu Region.
Red heavy rain (landslide) warnings: Saga and parts of Kumamoto prefectures in Kyushu Region.
Red flood warnings: Parts of Shimane Prefecture in Chugoku Region.
Yellow heavy rain (inundation), heavy rain (landslide), and flood advisories: Eastern Kanagawa Prefecture in Kanto Region; Gifu, Shizuoka, and Toyama prefectures in Chubu Region; Hyogo, Kyoto, Osaka, and Shiga prefectures in Kansai Region; Hiroshima, Shimane, parts of Tottori, and Yamaguchi prefectures in Chugoku Region. Tokushima and parts of Ehime and Kochi prefectures in Shikoku Region; and most of Kyushu Region.
Yellow thunderstorm advisories: Across most of Chubu, Chugoku, Kyushu, Kansai, Kanto, and Shikoku regions, as well as western Tohoku Region.
Yellow storm/gale warnings: Across much of the country.
Yellow high wave advisories: Across most coastal areas of Hokkaido, Honshu, and Kyushu islands.
Yellow melting snow and avalanche warnings: Across much of Hokkaido Prefecture and Tohuku Region.
Yellow dense fog warnings: Across much of Hokkaido Prefecture and parts of Chubu, Kanto, and Tohoku regions.
Officials could update and possibly extend the coverage of weather alerts over 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 remain possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.
Transport
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 areas heavily impacted by the adverse weather.
If strong winds trigger hazardous sea conditions, authorities may temporarily suspend port operations or close beach fronts. 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.
