Avalanche Bulletin
更新日時: 2025/02/21 06:30
Myoko
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
ストームスラブ Storm slab
Steep slopes with strong solar radiation have the potential for large avalanches.
概要
Avalanche
Yesterday (20th), an avalanche with a fracture line thickness of 1 m was observed on the eastern slope near the treeline. Due to poor visibility, detailed information is not available. In addition, several size 2.5 slab avalanches were observed below treeline in the adjacent Hakuba Mountains area. All are on the east slope.
Snowpack
Below treeline, the snow from the stormy weather since February 17 has been settling, reaching 80-100 cm. Vulnerability within the new snow is also slowing down the response to ski cuts. On the other hand, faceted snow has been observed on the upper surface of the Melt-Freeze crust (buried on February 17), and tests are showing cautionary results. The formation of this faceting 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 westerly winds, snow, and occasionally cloudy skies with a daytime high of 3 °C (13 m elevation) for the Joetsu region of Niigata Prefecture. At Sasagamine, Myoko (elevation 1,310 m), the temperature is -10 °C (as of 5:45 a.m.), and 1 cm of snow has fallen in the past 12 hours. At 5:30 a.m. on February 21, the Niigata District Meteorological Office is forecasting 40 cm of snowfall along the mountains of the Joetsu Region in the 24-hour period ending at 6:00 a.m. on February 22.
