Avalanche Bulletin
更新日時: 2025/01/17 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Low Increased skier triggered avalanche activity yesterday. With little observations in the alpine uncertainty exists.
Treeline Fair Confidence is good that multiple avalanche problems exist and avalanches are being triggered by riders. It is expected that this problem still exists today.
Below Treeline Good Skier triggered Loose snow and storm slab avalanches are expected today
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
With the frequency of skier triggered avalanches on the rise, remote triggers and persistent weak layers reported a stepping back mindset is recommended. Even with careful planning and travel techniques a remote triggered slide can catch you or your party off guard. These types of avalanches can be triggered from flat or lower on the slope angles and propagate into steeper terrain above you.
Avalanche Problem
持続型スラブ Persistent slab
There is a high degree of uncertainty in the existence reactivity and spacial distribution of the buried persistent weak layers. Further investigation is needed, more new snow further loads and increases the likelihood and the size of avalanches. The freezing level is forecasted to rise in a couple days, This often increases avalanche activity. After the warm up, when temperatures drop again persist weak layers often gain strength and become a non reactive problem.
ストームスラブ Storm slab
Storm slab avalanche activity has increased and more new snow will increase the likelihood of triggering storm slabs today.
点発生乾雪雪崩 Dry Loose snow
Loose dry avalanches continues to be a possible problem on very steep slopes today. You can be caught by your own sluff and carried into a terrain trap.
ウインドスラブ Wind slab
Confidence is low about the existence of wind slabs tree line and above.
概要
Avalanche
Numerous size 1, skier triggered, dry loose, and storm slabs were reported tree line yesterday Nito and Chise. Shiribetsu area Snowboarder triggered size 1 storm slab down 30 on 38 degree convex rollovers. No wind slabs were noted in the area. Kiroro: Storm slab Size 1 "Ski cutting small convexity to the side of planar slope at 1050m on N aspect of Nagamine. Shooting cracks went out from skis onto planar slope and triggered slide. Suspect it failed on buried Surface hoar down 30 cm as found on NE aspect earlier in day." North aspect 1050m 39 degree remote trigger 5 m wide ran 40+ m in track.
Snowpack
New snow continued to fall overnight. The top of the snow pack is getting more complex with crusts and weak layers buried. Storm and wind slabs have formed on top. Buried surface hoar, Surface facets have been reported 30-40 cm down. Skier triggered avalanches have increased.
Weather
Winter weather continues today. Light to moderate ridge top winds winds shifted over night to the NW over night and will continue today. Stronger winds are forecasted for the Yoichi area. More broken skies and less new snow expected Shiribetsu while the Niseko crest and Yoichi area will have snow and cloud all day. Temperatures will remain well below freezing at the surface the next several days
