New slabs have formed, which sit on a widespread weak layer. Conservative terrain travel is recommended.
Between 30 and 50 cm of snow fell across the region, forming storm slabs in areas sheltered from the wind and wind slabs at in exposed terrain at higher elevations. These slabs are expected to remain reactive to riders, as they overly a widespread layer of surface hoar crystals, faceted grains, and/or a hard melt-freeze crust on sun-exposed slopes.
A weak layer of faceted grains above a hard melt-freeze crust is buried around 120 to 250 cm deep. Although the likelihood of triggering this layer is expected to reduce given the current weather trend, the snowpack structure remains. Any release on this layer would be highly consequential.
MONDAY NIGHT: Cloudy with snowfall, accumulation 1 to 3 cm, 20 to 30 km/h west wind, alpine temperature -14 C.
TUESDAY: Cloudy with snowfall then clearing, accumulation 1 to 3 cm, 20 to 30 km/h northwest wind, alpine temperature -17 C.
WEDNESDAY: Increasing clouds with afternoon snowfall, accumulation 1 to 3 cm, 20 to 40 km/h southwest wind, alpine temperature -20 C.
THURSDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 20 to 40 km/h west wind, alpine temperature -13 C.
Many storm slabs and loose avalanches were triggered by riders on Sunday within the recent storm snow. The avalanches were most reactive where they sat on the surface hoar layer described in the snowpack summary.
Looking forward, human-triggering of avalanches may remain elevated, particularly where the recent snow overlies surface hoar.
Around 30 to 50 cm of snow fell on the weekend with strong wind, forming new storm slabs in sheltered terrain and wind slabs in exposed terrain. These slabs overly a widespread layer of weak surface hoar crystals that was reported as 5 to 15 mm in size, most prominent in terrain sheltered from the wind. The snow overlies a melt-freeze crust on sun-exposed slopes.
A few other weak layers of surface hoar and faceted grains exist in the top metre of snow but are reported as hard to find.
The facet/crust layer that formed in early December is buried around 120 to 250 cm. Although the last reported avalanche was about a week ago, the snowpack structure remains and it is a low probability but high consequence problem. Check out the forecaster blog for more information.
