Avalanche Bulletin
更新日時: 2025/02/05 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Fair Continued wind loading expected through the day with a change in Wind direction from SW to W
Treeline Fair Continued wind loading expected through the day with a change in Wind direction from SW to W
Below Treeline Fair Continued wind loading expected through the day with a change in Wind direction from SW to W
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Strong to Extreme winds and blowing snow will make travel at higher elevations very difficult today. Staying low in the trees will be a better choice. Make sure to consider overhead hazard from avalanche paths above you, and watch out for falling tree bombs. Upper snowpack structure varies greatly across the region, with multiple layers in different areas requiring careful assessment and conservative terrain choices.
Avalanche Problem
ウインドスラブ Wind slab
Continued Windslab formation expected through the day. Slabs are most reactive when they have just formed.
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 in the Northern part of the region (Kiroro, Kokusai). This layer is buried by 40-100cm of snow and has been triggered recently by skiers in areas where the buried Surface Hoar layer is well preserved.
概要
Avalanche
A natural size 1 Windslab was observed on a West asp BTL on Shiribetsu yesterday. In Kiroro shooting cracks were reported within the new Windslab, which indicates the potential for triggering a slab avalanche.
Snowpack
The Southern part of the region (Rusutsu) received 20cm of new snow last night. This was accompanied by strong SW winds which will have created new Windslabs and Cornice growth. Strong winds yesterday from the South affected the snowpack at all elevations, scouring windward aspects and forming new Windslabs on leeward aspects. There is a crust on solar aspects below the most recent storm snow. The Jan 28th PWL is of most concern in the northern part of the region where the surface hoar is well preserved. This PWL is down 40-100cm and consists of Surface Hoar, Facets and a Crust on solar aspects.
Weather
Strong to Extreme winds are forecast again today. Winds are expected to be South West this morning, shifting to West in the afternoon. Heavy snowfall is forecasted with 15-20cm expected by the end of the day. Temperatures will be colder today, in the -5 to -10 range at TL.
