Stormy conditions are creating very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Weak layers buried in late January or February may be reactive in isolated areas. Their distribution is uncertain, but it is most likely to be triggered on large slopes, where small surface avalanches could step down to the layer.
New snow and wind are forming fresh, reactive slabs and adding load to buried weak layers.
Loose wet avalanches will become increasingly likely as rain wets the upper snowpack at lower elevations.
A number of small (size 1) skier-triggered slabs were reported in the past couple of days, on north-facing convexities at alpine and treeline elevations. Crowns were around 30 cm deep.
On Tuesday, a natural size 3 avalanche ran on a buried weak layer on a treed west-facing knob.
During stormy conditions last week, a large avalanche cycle produced avalanches up to size 4, many likely stepping down to deeper weak layers. We may see similar activity this weekend.
New snow continues to accumulate over a variety of old surfaces. By the end of the day Saturday, 30 to 60 cm is expected, with snow turning to rain below 1200 m.
A layer buried in late January, consisting of surface hoar, facets, and/or crust, exists roughly 80 to 150 cm below the surface. Check out this blog post for more details on these problematic layers.
The remainder of the snowpack is well consolidated, with no significant layers of concern.
Friday Night
Cloudy. 10 to 25 cm of snow. 70 km/h west ridgetop wind. Treeline temperature -3 °C. Freezing level 1500 m.
Saturday
Cloudy. 10 to 30 mm of precipitation as snow or rain at treeline. 70 km/h west ridgetop wind. Treeline temperature -1 °C. Freezing level 1700 m.
Sunday
Mix of sun and clouds. 2 to 5 cm of snow. 50 km/h west ridgetop wind. Treeline temperature -5 °C.
Monday
Mix of sun and clouds. 4 to 5 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -10 °C.
More details can be found in the Mountain Weather Forecast.
