Japan: Adverse weather forecast across northern regions through at least Nov. 25

Adverse weather conditions are forecast across parts of northern Japan through at least Nov. 25. A storm system moving over the region will bring strong winds, snowfall, rough seas, and thunderstorms to parts of Hokkaido Prefecture, Tohoku Region, and Hokuriku Region over the coming days. Heavy downpours, lightning, hail, and possible tornadoes may accompany storms. Winds gusting up to 144 kph (89 mph) are possible across parts of Hokkaido Prefecture and up to 108 kph (67 mph) in parts of the Hokuriku and Tohoku regions. The combination of strong winds and snowfall could lead to blizzard conditions in some northern regions. Wave heights of up to 5 meters (16 feet) are expected in coastal parts of the affected region over the coming days.

As of Nov. 23, the Japan Meteorological Agency has issued the following weather warnings across Hokkaido, Hokuriku, and Tohoku:

• Yellow heavy rain and inundation warnings (the lowest level on a four-tier scale): Oshima Region in Hokkaido Prefecture

• Yellow heavy rain and flood warnings: Hiyama and Oshima regions in Hokkaido Prefecture

• Yellow storm/gale warnings: Abashiri, Hidaka, Hiyama, Ishikari, Kitami, Kushiro, Nemuro, Oshima, Rumoi, Shiribeshi, Sorachi, Soya, and Tokachi regions in Hokkaido Prefecture; Akita and parts of Yamagata prefectures in Tohoku Region; and across Hokuriku Region

• Yellow high wave warnings: Hiyama, Ishikari, Oshima, Rumoi, Shirbeshi, and Soya regions in Hokkaido Prefecture; parts of Akita, Aomori, and Yamagata prefectures in Tohoku Region; and most of Hokuriku Region

• Yellow thunderstorm warnings: Most of Hokkaido Prefecture; across Akita, Aomori, and Yamagata and parts of Iwate prefectures in Tohoku Region; and most of Hokuriku Region

• Yellow frost warnings: Parts of Fukushima Prefecture in Tohoku Region

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

The storm system could produce rounds of heavy precipitation (including rain and snow), strong winds, and isolated thunderstorm activity in affected areas. Where precipitation falls as rain, flash and areal flooding is possible. Such flooding is possible in low-lying communities near watercourses and other large bodies of water, as well as in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall.

Precipitation could fall as snow in parts of the regions over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in affected areas. Rain-induced landslides cannot be discounted in areas of elevated terrain; there is also the possibility of avalanches in mountainous areas where the snowpack has become unstable due to heavy snowfall. Power outages could occur throughout the affected area.

Floodwaters and related debris may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around the affected area. Flooding in urban areas could also result in significant traffic congestion. Heavy snow will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations. Mountain passes and tunnels could be closed as a precautionary measure during periods of intense snowfall.

The disruptive weather will likely cause some delays and cancellations at airports in parts of Japan. Authorities may temporarily suspend port operations along the Sea of Japan coast if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding or snow could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages.