Avalanche Bulletin
更新日時: 2023/02/06 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair 日射と昇温の影響に留意
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
In Treeline and Alpine, watch for wind slabs that have formed on specific terrain. Observe the slope features carefully and recognize the shape and slab formation that can easily destabilize the snowpack. If you see drifting snow, it is an indication that the snow is still moving and slab formation is in progress at this time. Avoid areas with wind slabs that are just forming. An avalanche danger rating of "1 low" does not mean that avalanches will not occur. Beware of unstable snow remaining on extreme terrain features. Have a good day.
Avalanche Problem
ウインドスラブ Wind slab
Vigilant of formation in characteristic isolated terrain.
概要
Avalanche
Yesterday (February 5), several size 1-2 slab avalanches were observed on the eastern slope from the treeline to the alpine. In the morning, numerous size 1 loose snow avalanches were observed on very steep slopes.
Snowpack
Yesterday, the 30-40 cm of new snow at the treeline had low cohesion in the morning and produced loose snow avalanches on very steep slopes. However, when the weather improved around noon, it subsided due to the effects of solar radiation and temperature rise, and changed to have the characteristics of a slab. Melt-Freeze crusts from the January 14 rainfall are deeply buried. However, it is relatively shallow in Alpine and is a cause for concern.
Weather
The Japan Meteorological Agency is forecasting northerly winds, clear skies, cloudy in the evening, and a high of 8°C (418 m elevation) for northern Nagano Prefecture. At the foot of Mt. Hakuba (elevation 703m), the temperature is -10.8°C (as of 5am), with no new snowfall in the past 12 hours.
