Friday's report of a remote-triggered wind slab is great data to help calibrate your exposure. The chance of a step-down avalanche underscores the importance of careful terrain selection.
We're gradually accumulating enough new snow for fresh, reactive slabs to form in leeward terrain features.
Importantly, wind slab avalanches may step down to deeper layers, resulting in larger avalanches.
A persistent weak layer is buried 1 - 2 m. This is a low-probability, high-consequence problem. Signs of instability may not be obvious. The best defence is smaller, low-consequence terrain.
We have a fresh observation of a remotely triggered wind slab in the Seaton area on Friday. Check out the MIN report here.
On Tuesday, the field team reported a cornice-triggered size 3 persistent slab on a northeast aspect. It ran to valley bottom and is a good example of the persistent problem affecting the region. There have been no other recent report of avalanches, but observations are limited.
If you are heading out, please submit a Mountain Information Network report!
About another 5 cm of new snow should accumulate by end-of day Saturday, adding to about 10 cm of new snow already redistributed by strong southwest winds, creating wind-pressed surfaces and wind slab in exposed alpine terrain. In more sheltered terrain, the new snow is burying 20 to 40 cm of older faceted snow. On steep solar aspects, particularly below 1700 m, it's likely burying sun crust.
A thick crust from late January can be found at a wide range of depths, from 75 to 150 cm. Where it is shallowest, facets are most likely to exist above it, and the more problematic it is expected to be.
We do not have concerns about the snowpack below this layer.
Friday Night
Mainly cloudy with scattered flurries bringing less than 5 cm of new snow. 20 to 40 km/h southwest ridgetop wind, easing. Treeline temperature around -4 °C.
Saturday
Mostly cloudy with scattered light flurries and a trace of new snow. 15 to 20 km/h southwest ridgetop wind, easing. Treeline high temperature -3 °C.
Sunday
Mostly cloudy with increasing flurries bringing up to 5 cm of new snow, light rain below about 1200 m. 20 to 30 km/h southeast ridgetop wind, increasing. Treeline temperature approaching 0 °C as freezing level climbs to 1400 m.
Monday
Mostly cloudy with some clearing near end-of-day. Increasing wet snowfall bringing 15 to 30 cm of new snow to higher alpine, diminishing with elevation to mainly rain below about 1200 m. 40 km/h south ridgetop wind. Treeline temperature 0 °C. Freezing level reaching 1500 m.
More details can be found in the Mountain Weather Forecast.
