Avalanche Bulletin
更新日時: 2025/02/09 05:30
Hakuba
Alpine Low
Treeline Fair Lack of information due to stormy weather
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Dangerous avalanche conditions continue. In all elevation zones, be on the lookout for steep slopes where the surface layer of snowpack has slab characteristics. Also, even if you are in the forest, consider whether there are avalanche start zones above you. Conditions are still present where very large avalanches can occur. Storm snow is very deep and soft. In some places it is difficult to get up after a fall. Be alert for "terrain traps" where even very small avalanches can bury you completely. Inexperienced skiers are advised to ski fresh snow in the ski area.
Avalanche Problem
ウインドスラブ Wind slab
Continuous strong north to northwest winds are blowing on the main ridge. We need to carefully observe the winds to see which elevations they descend to and where they form wind slabs.
ストームスラブ Storm slab
Beware of steep slopes where the surface layer of snow cover has the characteristics of a slab.
概要
Avalanche
Yesterday (8th), multiple size 1.5 storm slab avalanches were reported in the north area, below treeline, on east to south facing slopes. They were triggered by skiers. Some of these are bed surfaces with Melt-Freeze crusts buried on February 3. Due to stormy weather yesterday, there is no information at higher elevations.
Snowpack
The peak of snowfall has been exceeded, but there was some snowfall of 10-15 cm below treeline in the northern area. The storm snow so far has generally reached 190-210 cm. It has been observed that the underlying layer of storm snow has been slowly sintering and consolidating and gaining strength. However, avalanches have occurred due to human stimulation at several weak bonding points within the new snow. In addition, there remain concerns about the bonding conditions with the Melt-Freeze crust beneath this stormy snow. This Melt-Freeze crust is generally located below 1,400 m elevation and has the potential to cause large avalanches on the south face of Toomi One and Happo One. It will take time to resolve the great uncertainty here.
Weather
The Japan Meteorological Agency is forecasting northerly winds, cloudy, with occasional snow, and a daytime high of 1 °C (418 m elevation) for northern Nagano Prefecture. The temperature at Amedas Hakuba (elevation 703 m) is -5.1 °C (as of 5:00 pm), and there has been an increase of 4 cm of snow in the past 12 hours. The Nagano District Meteorological Observatory forecasted 30 cm of snowfall for northern Nagano Prefecture at 4:09 a.m. on February 9 in the 24-hour period ending at 6:00 a.m. on February 10. At the main ridge line (elevation 2,400 m), the temperature is -16°C with northerly winds averaging 15 m/s and 20 m/s maximum.
