Avalanche Bulletin
更新日時: 2025/02/02 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
This is the day to watch for unstable slabs that remain in certain terrains. Look closely at the slope angles, terrain geometry, and surface slab formations. Large open slopes facing south still have the potential for a large avalanche. The potential for triggering is low, but if it does occur, it will be a large avalanche. In other words, the risk can be described as high. Glide cracks below treeline are obscured by fresh snow. Take adequate precautions where the slopes change.
Avalanche Problem
ウインドスラブ Wind slab
Gale force winds ended yesterday morning and have since rapidly subsided. Therefore, today, beware of time-lapsed wind slabs. The snow surface may be hard, but depending on the terrain configuration, that slab may still respond to human stimulation.
ストームスラブ Storm slab
Imagine a feature terrain and yet, unstable snow. The slope angle is important.
点発生乾雪雪崩 Dry Loose snow
Currently, the snowfall is weak due to a low pressure system off the south coast. Depending on the amount of snowfall, please consider the possibility of a loose snow avalanche in the future.
概要
Avalanche
Yesterday (1st), many slab avalanches of size 2-2.5 were observed in the alpine, probably occurring in the last 24 hours. There was an incident on the east slope at 1,170 m elevation: after the second member of a three-person group skied, the snowpack fractured 7-8 m above his stop, resulting in a size 1.5 slab avalanche. Two people in the waiting position were caught in the avalanche, and one of them was swept 50 m down the slope, but was not buried. All were able to descend the mountain without injury.
Snowpack
At lower elevations, storm snow has been observed to be settling steadily. However, instability remains in terrain pockets, as evidenced by the reported incidents. On the other hand, on steep slopes east to south of the treeline, a combination of MFcr and Faceting snow has been observed in the mid-snowpack. Potential large-scale avalanche sources require further investigation.
Weather
The Japan Meteorological Agency is forecasting northerly winds, cloudy skies, snow in places until morning, and a daytime high of 6 °C (418 m elevation) for northern Nagano Prefecture. At Amedas Hakuba (elevation 703 m), the temperature is -2.2 °C (as of 5:00 a.m.), with no new snowfall in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -8 °C, with westerly winds averaging 1-3 m/s and a maximum instantaneous wind of 5 m/s.
