Flurries are starting to add up. Where the wind has moved the new snow into denser, deeper drifts, it may be possible to trigger slab avalanches.
Be alert to the potential for storm slabs to build throughout the day if the storm moves more quickly than anticipated.
Recent snow and southwest winds may have formed wind slabs in the alpine that could be reactive to human triggering. Use caution in wind-affected areas and watch for lee features with denser and deeper drifts.
Friday night: Mostly cloudy, flurries with 1-3 of accumulation, moderate southwest winds, alpine temperature -2 C, freezing level around 1500 m.
Saturday: Cloudy with periods of sun and snow with 2-5 cm possible, light to moderate southwest winds, alpine high temperature -3 C, freezing level around 1700 m
Sunday: Decreasing cloud cover, 5-15 cm of snow overnight with a trace during the day, light westerly winds, alpine high temperature -7 C, freezing level at valley bottom
Monday: Mix of sun and cloud, no precipitation, light variable wind, alpine high temperature -5 C, freezing level at valley bottom
There have been few recent avalanches reported in the region. A couple of small wind slabs triggered by explosives have been observed.
Large explosives in early season control work have triggered several large avalanches stepping down to deeper weak layers. While human triggering these larger avalanches remains unlikely in the short term, these results are indicative of persistent weak layers lingering in the snowpack that may become more reactive with additional loading.
An additional 2-5 cm of snow Friday brings the total to 10-15 cm from this week's scattered flurries. Ongoing southwest winds have likely drifted the recent snow into more cohesive slabs at upper elevations.
Crust layers from November and October can still be found deeper in the snowpack (check out this MIN report from Mear Lake). As the load on these weak layers increases with the incoming snow, these persistent weak layers could become more reactive.
Snowpack depths are highly variable this early in the season with amounts ranging between 50-100 cm at higher elevations and tapering rapidly below treeline.
