Avalanche Bulletin
更新日時: 2025/02/07 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Fair Conservative terrain choices are advised
Treeline Fair Conservative terrain choices are advised
Below Treeline Fair Conservative terrain choices are advised
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Conservative terrain choices are the best way to manage the Jan 28th Persistent Slab avalanche problem. Assess new windloading that will have occurred overnight and make sure to consider overhead avalanche hazard. Sheltered trees will hold the best quality snow.
Avalanche Problem
ウインドスラブ Wind slab
Overnight winds will have created fresh Windslabs and Cornice growth.
点発生乾雪雪崩 Dry Loose snow
Use caution in steep features with terrain traps: creeks, gullies, etc.
持続型スラブ Persistent slab
A layer of Surface Hoar, Facets and a Crust that was buried on January 28th is still a concern. An avalanche was triggered on this layer in the Shiribeshi area yesterday. Conservative terrain choices are the best way to manage a Persistent Slab problem. Uncertainty exists with the distribution both with regards to location and elevation of this problem. Most observations show it to be a concern in the northern part of the region at TL and BTL
概要
Avalanche
A size 1 Persistent Slab was triggered on a SE asp BTL yesterday in the Shiribeshi area. This avalanche was 45cm deep and failed on the Jan 28th crust PWL. Reactive Cornices were reported at Rusutsu yesterday on NE asp at TL. Loose Dry avalanches were triggered at Kokusai yesterday on steeper terrain.
Snowpack
20-40cm new snow overnight across the region. This was accompanied by Moderate West winds, creating new Windslabs and Cornice growth. Most areas have been wind affected over the past 3 days, with sheltered BTL holding the best quality snow. An extended column snowpack test on a SE asp BTL in the Kiroro backcountry on Wednesday produced a clean failure down 70cm on a layer of Facets above the Jan 28 crust that crossed the whole column in one tap, indicating the potential for a slab avalanche to occur on this layer. A slab avalanche was also triggered on the Jan 28 crust down 45cm in the Shiribeshi area yesterday. This shows that the Jan 28 PWL needs some more time to bond to the snow above, and should still be considered when choosing terrain to ride.
Weather
5-10cm of snowfall expected through the day. Winds are decreasing to Moderate from the West today. Skies will be overcast and temps will be in the -5 to -10 range at TL.
