Avalanche Bulletin
更新日時: 2025/02/08 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Very dangerous avalanche conditions. At higher elevations, the weather is too rough for action. On the other hand, even below treeline, avalanches of great magnitude can occur on large open slopes facing south. Even when operating in the forest, pay maximum attention to the terrain and consider whether there is an avalanche start zone above you. When visibility is poor, such hazards are less likely to be noticed. The storm snow is very deep, and even a very small avalanche can bury you if you fall in a small depression. For inexperienced groups, skiing is recommended. When doing so, do not enter closed areas. It is important not only for your safety, but also for the safety of other guests.
Avalanche Problem
ストームスラブ Storm slab
Maximum attention to terrain, even in the forest
ウインドスラブ Wind slab
Even below treeline, open slopes can be subject to avalanches of large magnitude.
概要
Avalanche
A size 2.5 (fracture line 1.5 m) storm slab avalanche occurred spontaneously on the south slope of the below treeline early yesterday (7th). A size 1 avalanche has also been reported. Weather conditions are poor and no information has been received at higher elevations.
Snowpack
Below treeline, it appears that 30-40 cm of snow had fallen by this morning. The storm snow so far has generally reached 150-170 cm. It has been observed that the underlying layer of storm snow is slowly sintering and consolidating and gaining strength. However, avalanches have occurred due to human stimulation at several weak bonding points within the new snow. There are also concerns about the bonding conditions with the Melt-Freeze crust beneath this storm snow, and yesterday a large avalanche spontaneously occurred at the boundary between storm snow and Melt-Freeze crust.
Weather
The Japan Meteorological Agency is forecasting northerly winds, snow, late afternoon to early afternoon, cloudy, and a daytime high of 1 °C (418 m elevation) for northern Nagano Prefecture. At Amedas Hakuba (elevation 703 m), the temperature is -6.9 °C (as of 5:00 a.m.), and there has been 14 cm of snow accumulation in the past 12 hours, and 17 cm in the past 24 hours. The Nagano District Meteorological Observatory forecast 40 cm of snowfall for northern Nagano Prefecture at 4:17 a.m. on February 8 in the 24-hour period ending at 6:00 a.m. on February 9. At the main ridge line (elevation 2,400 m), the temperature is -19°C, with northerly winds averaging 25 m/s and maximum wind speeds of 30-40 m/s.
