Japan: Winter weather forecast over parts of Honshu and Hokkaido through at least Jan. 1 /update 2

Event

Winter weather, including heavy snow, is forecast across parts of Honshu and Hokkaido through at least Jan. 1. The Japan Meteorological Administration has warned of heavy snowfall from northern to western Japan, especially along the Sea of Japan coast. Yellow dry air, low temperature, and avalanche advisories are in place across much of the affected area. Authorities will likely issue new warnings or update existing advisories in the coming days; officials may issue evacuation orders if weather conditions persist or worsen.

Power outages have been reported across at least 10 houses in Kyoto Prefecture, 430 houses in Shiga Prefecture, and 50 houses in Fukui Prefecture. Due to adverse weather conditions, Yamato Transport and Sagawa Express courier companies have canceled the delivery and storage of packages in parts of Aomori, Hokkaido, Hyogo, Shiga, and Tottori prefectures. Delivery is also delayed in other prefectures. At least one fatality has occurred in Oirase Town, Aomori Prefecture, early Dec. 28 when a snow removal vehicle fell into the gutter.

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
The winter weather will likely cause ground and air transport disruptions over the coming days. Traffic and commercial trucking delays are possible along regional highways. Difficult and dangerous driving conditions are also likely on secondary and rural roads in the affected states as maintenance crews prioritize clearing major routes. Authorities could close stretches of highway if driving conditions become too hazardous. Parts of National Highway 8 and the Hokuriku, Isewangan, Mei-Nikan, Meishin, Tokai-Hokuriku, Tokai-Kanjo, and Shin-Meishin expressways are closed due to the heavy snow. Gusty winds may threaten to topple high-profile vehicles throughout the affected area. Severe weather could also trigger flight delays and cancellations at regional airports. Authorities have canceled at least 25 flights from Toyama Airport (TOY), 21 flights from various airports across Hokkaido Prefecture, and at least two flights between Osaka International Airport (ITM) and Kounotori Tajima Airport (TJH) in Hyogo Prefecture.

Officials may temporarily suspend port operations or close beach fronts along the Sea of Japan and the North Pacific Ocean 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. Authorities have suspended or delayed multiple trains due to heavy snow. Tokaido Shinkansen is reducing speed between Shin-Osaka and Toyohashi stations in Aichi Prefecture due to the heavy snow, resulting in delays on the Sanyo Shinkansen. Due to a collision with a tree on the JR Senzan Line early Dec. 28, all trains are suspended between Ayashi Station in Sendai City and Yamagata Station in Yamagata City.

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