Avalanche Bulletin
更新日時: 2025/01/16 05:30
Hakuba
Alpine Fair
Treeline Low Degree of wind impact unknown.
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Yesterday's extremely dangerous avalanche conditions are dissipating, but there are still more than enough conditions to be cautious. Entering large open slopes, even below treeline, is not recommended. Especially on steep south-facing slopes, Melt-Freeze crusts are buried under fresh snow and have the potential to create large avalanches. The best means of lowering avalanche risk is to choose gentle slopes. However, the large amount of powder snow prevents speed. As a result, we tend to head for steep slopes that are ideal for avalanches. Today, as yesterday, is a good day to enjoy powder snow in the ski resort. When enjoying powder snow courses, use the "buddy system" of skiing with a friend. Some accidents have occurred where people have been buried in deep snow and suffocated, not avalanches.
Avalanche Problem
ストームスラブ Storm slab
Due to the low temperatures, it will take time to resolve the instability. In addition, the large amount of snow that fell yesterday with low cohesion caused many avalanches of very soft slabs. Today, the snow that made up those soft slabs is sintering and making up more solid slabs. This makes larger avalanches more likely to occur.
ウインドスラブ Wind slab
Currently, the wind has subsided on the main ridge, but extremely strong northwest to north winds have been blowing on the main ridge until late yesterday night. A large amount of new snow has been moved downwind by this wind, forming wind slabs. The high density of slabs on top of the low cohesion snow has resulted in the appearance of many areas of inverse structure, which is typical of unstable snowpack.
概要
Avalanche
Yesterday (15th), a very large number of storm slab avalanches (size 1-2) occurred during morning control operations at the ski resort. Due to the very dangerous conditions, measures were also taken to close some courses. Due to these conditions, no data is available for the mountain area.
Snowpack
This massive snowfall is about 100 cm below treeline. Stabilization of the new snowfall will be slower due to lower temperatures than yesterday (5:00 AM on the 16th; 1,570 m, -11°C, 2,400 m, 16°C). In addition, northwest to north winds averaging 15 m/s and maxing out at 25 m/s or higher were blowing on the main ridge from noon to midnight yesterday. As a result, the snowfall itself is subsiding, but a large amount of new snow is being moved by the wind.
Weather
Today, Hakubavallery will be moderately covered by high pressure, but is expected to be affected by a pressure trough and cold air. The Japan Meteorological Agency is forecasting northerly winds, later southerly winds, cloudy, sunny in the afternoon and evening, partly snowy in the morning and evening, and a daytime high of 3 °C (418 m elevation) for northern Nagano Prefecture. At Amedas Hakuba (elevation 703 m), the temperature is -4.6 °C (as of 5:00), and there has been no increase in snow depth in the past 12 hours.
