Avalanche Bulletin
更新日時: 2023/01/23 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
The recent snow was settling and the avalanche danger is decreasing. However, very steep south-facing slopes at the Treeline are creating some nasty instability and should be avoided. Even if the weather improves today, it is a phenomenon known as pseudo-favorable weather. Very strong cold air will move in toward tomorrow and it will be very rough. Please use an early action plan to descend the mountain. There are numerous "terrain traps" hidden in the forest, please be careful.
Avalanche Problem
ウインドスラブ Wind slab
ストームスラブ Storm slab
Watch out for very steep slopes facing south.
概要
Avalanche
Yesterday (January 22), a size 1.5 slab avalanche or shooting crack was observed on an isolated terrain or wind-affected slope.
Snowpack
The ice or Melt-Freeze crusts formed by the January 14 rainfall have been buried by the subsequent snowfall (20-30 cm). In areas where the wind is strong, the crusts are exposed and also hard, but in other areas, they are hard enough to be stepped through. On steep slopes near Treeline, faceted snow has formed on top of this Melt-Freeze crust, and investigations have shown that this is the cause of the whumpfing sound and remote-triggered avalanches reported on January 21. We need to watch for further changes in this weak layer.
Weather
The Japan Meteorological Agency is forecasting winds from the south, later from the north, cloudy, sunny before noon and in the evening, with a maximum temperature of 7°C (418m elevation) for northern Nagano Prefecture. At the valley of Hakuba (elevation 703m), the temperature is -4.3°C (as of 5:00), with no new snowfall in the past 12 hours.
