Japan to Experience Severe Snowstorms

Affected by an upper-level cold vortex system (Figure 1), it is expected that from December 31 to January 3, 2026, most regions of Japan will experience moderate to heavy snowfall. Specifically, parts of Hokkaido, Tohoku, Chubu, Kinki, and the eastern areas of Chugoku will see severe to extreme blizzard conditions, with localized areas experiencing extraordinary heavy snowfall. The cumulative snowfall during this period is anticipated to be between 10 and 30 millimeters, with localized areas reaching 50 to 80 millimeters (Figure 2). The 24-hour new snow accumulation depth is expected to range from 6 to 12 centimeters, with some areas exceeding 20 centimeters. Additionally, strong winds of 6 to 7 on the Beaufort scale are forecasted, with gusts reaching 8 to 9 (Figure 3).

Attention should be given to the adverse impacts of severe wind and snow conditions on local power infrastructure, transportation, and other industries.

Figure 1  Forecast of 500 hPa Geopotential Height (Unit: dagpm) and 850 hPa Wind Field at 00:00 (UTC) on January 1, 2026 (Unit: m/s)

Figure 2  Accumulated Snowfall from 00:00 on December 31 to 12:00 on January 3, 2026 (UTC, Unit: mm)

Figure 3  Maximum Gust Speed (Unit: m/s) for 24 Hours as of 12:00 (UTC) on January 1, 2026

 Author: Yan Dachun                             Reviewer: Zhou Ningfang

 English reviewer:  Wang Yi                                                                       Issue approver:  Dai Kan