Avalanche Bulletin
更新日時: 2025/02/05 05:30
Hakuba
Alpine Fair 今後の降雪の程度による
Treeline Fair Depends on the degree of wind and snow in the future.
Below Treeline Fair Depends on the degree of snowfall in the future.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Dangerous avalanche conditions. Watch out for storm slabs that form on steep slopes and wind slabs that form from wind-moved snow. It is important to pay attention to the meeting point and choose a location with a large margin of safety. Glide cracks that have formed previously are harder to spot. Do not feel safe in the woods and be alert to where the angle of the slope changes.
Avalanche Problem
ストームスラブ Storm slab
Beware of very steep slopes and terrain that is convex or unsupported, where the snowpack can become unstable. Even below treeline, open steep slopes, such as open gullies, are more hazardous.
ウインドスラブ Wind slab
Northerly winds are increasing, so be on the lookout for slopes affected by them. The winds will turn around along the slopes and slabs will form on the sides of the branch ridges, so be aware of those as well.
概要
Avalanche
Yesterday (4th), multiple size 1.5 storm slab avalanches were reported in the below treeline. They were induced by skiers or by ski cuts. Several size 1 dry loose snow avalanches were also reported.
Snowpack
The snow from this storm, which began on the 3rd at higher elevations, was about 40 cm around the treeline as of yesterday. It has accumulated under relatively weak wind influence, causing small loose snow avalanches on very steep slopes. On the other hand, on slopes with some wind influence, it forms soft slabs and is sensitive to human stimulation, causing avalanches. Information on the interface between this storm snow and old snow is limited and uncertain. Here is a listing of about 15 cm of snowfall that began earlier today. The amount of new snow is higher in the northern areas of the Hakuba Valley.
Weather
The Japan Meteorological Agency is forecasting southerly winds, cloudy, with occasional snow, and a daytime high of 3 °C (418 m elevation) for northern Nagano Prefecture. The temperature at AMeDAS Hakuba (elevation 703 m) is -6.1 °C (as of 5:00 pm), with no new snowfall in the past 12 hours. The Nagano District Meteorological Observatory is forecasting 40 cm of snowfall for northern Nagano Prefecture at 4:14 a.m. on February 5 in the 24-hour period ending at 6:00 a.m. on February 6. At the main ridge line (elevation 2,400 m), the temperature is -19°C, with northerly winds averaging 15 m/s and max. wind speeds of 25 m/s.
