Avalanche Bulletin
更新日時: 2025/02/21 05:30
Hakuba
Alpine Fair
Treeline Low Lack of information due to stormy weather
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Although the winter pressure pattern is weakening and snowfall is decreasing, avalanche conditions are turning difficult. This is because the snowpack intensity is changing from place to place. Avoid isolated terrains that are convex and unsupported, and look for simple terrains with little wind influence. Also, crusts (buried on February 17) are a concern on steep slopes that are highly affected by solar radiation. If an avalanche is triggered in an area with a thin snowpack, it can collapse into thickly accumulated areas, which can lead to large avalanches. Since the snow in stormy weather is settling, even if the slope is made a little slower, you can still enjoy comfortable fresh snow skiing. And, making the slope slower is the most effective way to prevent avalanches.
Avalanche Problem
ウインドスラブ Wind slab
Wind slabs that have been hardened over time can be tricky to handle. Be wary of slabs in isolated terrain.
ストームスラブ Storm slab
Steep slopes with strong solar radiation influence facing east to southwest have the potential for avalanches of large magnitude.
概要
Avalanche
Yesterday (20th), several size 2.5 avalanches were observed on the eastern slope of the below treeline. No information was received at higher elevations due to stormy weather.
Snowpack
Below treeline, storm snow since February 17 has advanced settling to 50-70 cm. Regarding the vulnerability within the new snow, the response to ski cuts is also slowing down. On the other hand, faceted snow has been observed on the upper surface of the Melt-Freeze crust (buried on February 17), which should be noted in the test results. The formation of this faceted snow is uneven, with some areas showing test results and others not. At higher elevations, there is a lack of observational data due to stormy weather, and great uncertainty exists.
Weather
The Japan Meteorological Agency is forecasting northerly winds, cloudy, occasionally sunny, snowy in places, and a daytime high of 2 °C (418 m elevation) for northern Nagano Prefecture. At Amedas Hakuba (elevation 703 m), the temperature is -8.5 °C (as of 5:00), and 2 cm of snow has fallen in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -18 °C (as of 5:00), with northerly winds averaging 11 m/s and a maximum of 13 m/s at the moment.
