15 Dec 2022 | 12:15 PM UTC
Japan: Adverse weather forecast to continue across northern and western regions through at least Dec. 16 /update 1
Snowfall, strong winds, and thunderstorms are forecast across northern and western Japan through at least Dec. 16. Possible disruptions.
Event
Adverse weather conditions are expected to continue across parts of northern and western Japan through at least Dec. 16. A storm system moving over the regions from the Sea of Japan will bring strong winds, snowfall, rough seas, thunderstorms, and heavy rainfall. Snowfall is most likely over parts of northern Japan and storms could be accompanied by heavy downpours, lightning, and possible tornadoes in parts of the Hokuriku and Tohoku regions along the Sea of Japan coast. Winds gusting up to 126 kph (78 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.
As of late Dec. 15, the Japan Meteorological Agency has issued the following weather warnings across Hokkaido, Hokuriku, and Tohoku regions:
Red snowstorm warnings (the middle level on a three-tier scale): Hiyama, Ishikari, Oshima, Rumoi, and Shiribeshi regions in Hokkaido Prefecture.
Red heavy snow warnings: Parts of Yamagata Prefecture in Tohoku Region.
Red heavy rainfall and landslide warnings: Parts of Ishikawa Prefecture in Hokuriku Region.
Red high wave warnings: Parts of Ishikari, Rumoi, and Shiribeshi prefectures in Hokkaido Prefecture.
Yellow snowstorm warnings: Hidaka, Iburi, Kamikawa, Sorachi, and Soya regions in Hokkaido Prefecture and Akita, Aomori, and parts of Yamagata prefectures in Tohoku Region.
Yellow heavy snow warnings: Ishikari, Kamikawa, Oshima, Rumoi, Shiribeshi, and Sorachi regions in Hokkaido Prefecture and Aomori and inland areas of Akita and Iwate prefectures in Tohoku Region.
Yellow heavy rainfall and landslide warnings: Across Toyama and parts of Fukui, Ishikawa, and Niigata prefectures in Hokuriku Region.
Yellow storm/gale warnings: Abashiri, Kushiro, Mombetsu, Nemuro, and Tokachi regions in Hokkaido Prefecture and across Hokuriku Region.
Yellow high wave warnings: Abashiri, Hidaka, Hiyama, Kushiro, Mombetsu, Nemuro, Oshima, Soya, and Tokachi regions in Hokkaido Prefecture; Aomori and parts of Akita and Yamagata prefectures in Tohoku Region; and most of Hokuriku Region.
Yellow thunderstorm warnings: Akita and Yamagata prefectures in Tohoku Region and across Hokuriku Region.
Yellow dry air warnings: Kushiro, Nemuro, and Tokachi regions in Hokkaido Prefecture.
Yellow avalanche warnings: Ishikari, Kamikawa, Oshima, Rumoi, Shiribeshi, Sorachi, and Soya regions in Hokkaido Prefecture; across Aomori and parts of Fukushima, Iwate, and Yamagata prefectures in Tohoku Region; and parts of Niigata Prefecture in Hokuriku Region.
Yellow snow accretion warnings: Across Aomori and parts of Akita, Iwate, and Yamagata prefectures in the Tohoku Region.
Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.
Hazardous Conditions
The storms 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 northern 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.
Transport
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.
Advice
Monitor local media for weather-related updates and advisories. Confirm all transport reservations and business arrangements before traveling in affected areas. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions throughout the affected areas. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides, as well as mountainous regions where avalanches pose a threat. Charge battery-powered devices in the case of prolonged electricity outages.
