Avalanche Bulletin
更新日時: 2025/01/22 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
At higher elevations, be alert for new wind slabs formed by winds that have been strengthening since last night. Avoid areas where the snowpack is likely to be unstable, such as convex, unsupported terrain. Wide open alpine slopes can skew your sense of slope. If you are sensitive to slope and see a tendency toward wind slab on the snow surface, it is time to choose another route. There are many deep glide cracks forming below treeline. Be careful of the change in slope.
Avalanche Problem
ウインドスラブ Wind slab
Since last night, there has been a northerly wind blowing on the main ridge that has been scraping even the hard snow surface. Watch out for wind slabs that have formed as a result of this wind scouring and redistribution to the downwind side.
全層雪崩 Glide slab
Glide crack enlargement has also been observed at lower elevations.
概要
Avalanche
Yesterday (21st), a size 1.5 wind slab avalanche was reported in isolated steep terrain at higher elevations. It was caused by a slab that formed on the same day. A size 2 glide avalanche was also reported at a lower elevation, as well as an enlarged glide crack.
Snowpack
The higher elevation northern slopes have well-dried, settled snow, while the lower elevation southern slopes have Melt-Freeze crusts that have formed due to sunny slopes and high temperatures. On the main ridge, strong northwest winds blew yesterday morning, causing snow plumes to rise. The slabs that formed due to this effect were causing avalanches in extreme terrain. The winds died down yesterday afternoon, but picked up again last night and this morning, and are now strong northerly winds (average 17 m/s).
Weather
The Japan Meteorological Agency is forecasting northerly winds, sunny, occasionally cloudy, and a daytime high of 7 °C (418 m elevation) for northern Nagano Prefecture. At AMeDAS Hakuba (elevation 703 m), the temperature is -8.2 °C (as of 5:00 a.m.), with no new snowfall in the past 12 hours. Alpine (elevation 2,400 m) has a temperature of -11.5 °C (as of 5:00) with an average wind speed of 17-18 m/s.
