Avalanche Bulletin
更新日時: 2025/02/16 05:00
Niseko Yotei Yoichi Shiribeshi
Alpine Fair A rapid rise in temperature today greatly increases the avalanche hazard.
Treeline Good A rapid rise in temperature today greatly increases the avalanche hazard.
Below Treeline Good A rapid rise in temperature today greatly increases the avalanche hazard.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Monitor the rapid rise in temperature and its effect on the snowpack. Lower elevations will be most impacted by the rising temperatures. Its a good day to start early and finish early before the temperature rises above 0C. Today`s temperature spike is not driven by solar input so it will affect all aspects including North`s. Conservative terrain choices are prudent while the snowpack adjusts to the temperature spike. Tree bombs can be expected to continue falling today.
Avalanche Problem
ウインドスラブ Wind slab
Windslab exists lee to previous westerly winds. Today`s SW winds will change the loading pattern and re-destribute any snow available for transport to slopes lee to the SW wind.
ストームスラブ Storm slab
The temperature spike today will continue to promote slab development and increase the reactivity of the storm slab.
全層雪崩 Glide slab
Rising temperatures will cause melting within the snowpack and increase the likelihood that glide cracks will open up. It is rare but possible for glide cracks to release as large scale, full depth avalanches.
概要
Avalanche
2 x size 2 Skier accidental Windslab avalanches were reported on an East aspect at Shiribetsu yesterday. The windslab became reactive due to rapid settlement and rising day time temperatures. Multiple size 2 natural avalanches were also triggered on the Shakotan peninsula by cornices collapsing.
Snowpack
Warm, sunny weather across the region yesterday cause rapid settlement of the storm snow. Storm snow is now 20-40cms deep. There may be a density inversion below this layer before density steadily increases down to the Jan. 28th PWL.
Weather
A weak low pressure system to the West of Hokkaido brings a light WSW flow across the region today. This will bring a rapid rise in temperature with freezing levels climbing to 600m and valley temperatures reaching a high of 6C late in the afternoon. Skies will be mostly overcast with light precipitation expected to start around noon. Lower elevations will receive rain while higher elevations will receive moist snow. Winds are forecasted to be light SW for most of the day.
