Avalanche Bulletin
更新日時: 2025/01/24 05:30
Hakuba
Alpine Low Exact amount of snowfall unknown
Treeline Fair
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
This is a day of high avalanche conditions in certain locations. Be on the lookout for very steep slopes where the interaction of terrain and wind has caused new snow to accumulate since yesterday. There is a hard Melt-Freeze crust buried to the south that is suitable for avalanches, so even small avalanches can easily flow long distances. Look for simple terrain, avoiding areas where the upper snowpack is convex or unsupported with slab features. Numerous glide cracks are appearing in the forest as well. Careful route selection is required. Have a good weekend.
Avalanche Problem
ストームスラブ Storm slab
Very low cohesion snow fell yesterday. Where the amount of new snow is at least as high and the surface layer of the snowpack has the characteristics of a slab, consider that the conditions are such that avalanches can be triggered by human irritation.
点発生乾雪雪崩 Dry Loose snow
Watch out for very steep gullies with snow accumulation, etc. Check for "terrain traps" below you.
概要
Avalanche
Yesterday (23rd), a size 1 dry loose snow avalanche with a ski cut was observed on a steep slope north of the treeline. This was caused by fresh snow that began falling before noon at higher elevations. A size 2 glide avalanche was also observed below treeline, which occurred within a few days.
Snowpack
Weak snowfall has been observed at higher elevations since around noon yesterday (23rd) due to a pressure trough in the upper air. The amount of snowfall was 10-15 cm at the northern treeline of the Hakuba Valley. An additional 10 cm of snow had fallen by this morning. These new snowfalls are on hard Melt-Freeze crusts on the southern steep slopes and on settled old snow on the northern slopes. Meanwhile, at elevations below 1,000 m, light rainfall since yesterday evening has left the snow in a wet condition.
Weather
Today, high pressure is expected to prevail, but the area will be affected by a pressure trough and moist air. The Japan Meteorological Agency is forecasting northerly winds, cloudy, sometimes sunny, with snow or rain in the afternoon, and daytime high temperatures of 7 °C (418 m elevation) for northern Nagano Prefecture. At AMeDAS Hakuba (elevation 703 m), the temperature is -0.7 °C (as of 5:00 am), with no new snowfall in the past 12 hours. At Alpine (elevation 2,400 m), the temperature is -10.8 °C (as of 5:00) with an average NW wind speed of 11 m/s.
