Avalanche Bulletin
更新日時: 2025/02/13 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Fair Limited alpine obs
Treeline Good NW winds will continue to build windslab and cornices
Below Treeline Good Cooler temps will reduce the likelihood of storm slab formation
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
More new snow over the past 24 hours adds to already deep conditions in the backcountry. Snow immersion is a significant hazard so always ski with a friend and keep an eye on each other. Yesterday`s warm temps also released widespread tree bombs which are ice hard and now buried under new snow - ski and ride the trees with caution. Be aware of windslab development on leeward slopes, cornice growth and monitor instabilities within the storm snow.
Avalanche Problem
ウインドスラブ Wind slab
The storm was accompanied by moderate to NW strong winds which has accelerated cornice development and loaded leeward slopes.
ストームスラブ Storm slab
Cooler temps today will help tighten up the storm snow however instabilities may remain.
点発生乾雪雪崩 Dry Loose snow
Loose dry avalanches can be expected to run on steep slopes today.
概要
Avalanche
No new avalanches were reported yesterday.
Snowpack
15-30cms of new snow fell overnight in the mountains. This followed a warm period yesterday that brought rain and moist snow to lower elevations before the temperatures dropped back below freezing in the evening. As a result of this transition, the storm snow in sheltered areas will be right side up with density increasing however a density inversion exists below the overnight snow. NW winds have re-distributed new snow to leeward slopes and density inversions may be possible on these aspects. Additional storm instabilities exist within the upper snowpack however in general it is rounding and settling. The Jan. 28 PWL is 1-2 meters deep. Melt Freeze crusts also exist on solar aspects in some parts of the region at varying depths.
Weather
A low pressure system to the East of Hokkaido draws a NW flow across the region. Steady snow is expected through the most of the day with accumulations of 5-15cms. Winds will be moderate to strong from the NW and skies are expected to be overcast all day. Temps will remain cool through the day with a high of -3C in the valley today.
