Avalanche hazard will rise with an incoming winter storm on Thursday. I'm expecting most areas to see around 25 cm of new snow by the end of Thursday. If storm amounts build up to 35 cm or more, consider the alpine and treeline avalanche danger to be high.
Natural avalanches are likely to start running on steep slopes when accumulations reach approximately 35 cm of new snow. On windy slopes, this threshold will be reached much sooner and their dense nature will make them easier to trigger.
Wednesday night: Around 10 cm new snow. Strong Southwesterly ridgetop winds.
Thursday: 15-20 cm new snow. Freezing levels rising to approximately 1400 m in the afternoon. Moderate
southwesterly winds at treeline elevations, strong or extreme southwesterly winds at ridgetop.
Friday: Around 10 cm new snow. Freezing level around 1400 m. Strong southwesterly ridgetop winds.
Saturday: Some clear spells in the morning. Around 5 cm new snow in the afternoon. Freezing levels at valley bottom. Moderate southwesterly ridgetop winds.
Recent size 1.5-2 wind slab avalanches have been reported from exposed locations at higher elevations (above approximately 2000 m) on various aspects.
Expect avalanche activity to increase as the storm builds through the day on Thursday.
20-50 cm of recent snow sits above a rain crust from mid-November. This rain crust exists at elevations to at least 1800 m and potentially up to 2100 m. The wind has moved the recent snow into wind deposits in exposed alpine areas.
