Avalanche Bulletin
更新日時: 2025/03/08 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Conditions require caution in certain terrain. Yesterday's strong winds have created wind slabs, and beneath the slabs are hard Melt-Freeze crusts. This is a snowpack structure that can easily trigger avalanches, and even small avalanches can slide off and cause serious consequences. In addition, the previous rough snow surface is hidden under the new snow, making it difficult to ski. Snow blocks that have fallen from trees are very hard and can cause injuries and falls. Please ski with caution.
Avalanche Problem
ウインドスラブ Wind slab
Underneath the slab is a hard snow surface, making conditions highly reactive to human stimulation. Observe the snow surface conditions carefully and notice the slab formation. And avoid terrain that is convex or unsupported.
ストームスラブ Storm slab
In areas where the wind is weak, observe if the upper layer of snow cover has the characteristics of a slab. If the new snow on the melting crust has an inverse structure, consider the conditions to be inducible.
概要
Avalanche
Yesterday (7th), a size 1 dry loose snow avalanche and a slab avalanche occurred by ski cut below treeline in the north area where there was heavy snowfall. No information has been received at higher elevations.
Snowpack
The snowfall from the night of March 6 through yesterday was on top of the Melt-Freeze crust formed by the March 5 rainfall. The snow began accumulating at low density and was then heavily redistributed by winds that strengthened during the day on the 7th. This is expected to result in the formation of unstable wind slabs, especially at higher elevations. In addition, the slab avalanches that occurred yesterday were caused by the sintering of snow due to incoming solar radiation, which caused the new snow to take on the characteristics of a slab. Consider that slabs on steep slopes that are highly affected by incoming solar radiation may become more reactive to human stimulation today as well.
Weather
The Japan Meteorological Agency is forecasting northerly winds, cloudy skies, snow in places from midday, and a daytime high of 7 °C (418 m elevation) for northern Nagano Prefecture. At Amedas Hakuba (elevation 703 m), the temperature is -7,9 °C (as of 5:00 am), and 1 cm of snow has fallen in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -9 °C (as of 5:00), with northerly winds averaging 8 m/s and a maximum instantaneous wind speed of about 10 m/s.
