Avalanche Forecast

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Saturday night: Increasing cloud, moderate southwest ridgetop wind, freezing level valley bottom.

Sunday: Sun and cloud, isolated flurries, moderate to strong south ridgetop wind, alpine high -5C, freezing level valley bottom.

Monday: Scattered flurries, moderate southwest ridgetop wind, alpine high -8 C, freezing level 500 m.

Tuesday: 5-10 cm new snow, strong southwest ridgetop wind, alpine high -5 C, freezing level 800 m.

On Sunday, as the wind picks up, we can expect to see natural and human triggered wind slabs in lee features at upper elevations.

Since Wednesday, natural avalanche activity has been limited to loose dry sluffs of diminishing size.

A widespread natural cycle occurred during the storm Monday night through Tuesday, storm slabs size 2-3 and loose wet size 1-2.

On Tuesday December 1, a large size 3 natural avalanche was observed on a NE aspect at 2400 m in the Duffy area. It was reported as a cornice failure triggering the slope below and appeared to have slid on the early November crust near the base of the snowpack.

Have you been out and about in the mountains? If so please submit your observations to the Mountain Information Network (MIN). It doesn't have to be technical - photos are especially helpful! Thank you so much for all the great MINs submitted so far! 

At upper elevations, winds are forecast to pick up during the day Sunday. The will likely redistribute into wind slabs the 10-30 cm of dry snow that sits over a crust.

• In the south, 20-30 cm of dry surface snow bonds to the underlying crust formed earlier this week when 25 mm of rain soaked the upper snowpack at all elevations. We've got our eye on a couple of crusts in the upper to mid snowpack that are producing moderate to hard snowpack test results. Treeline snowpack depth sits around 80-130 cm.

• In the north, around 30 cm of recent snow sits over a thin zipper crust above 2300 m, snow tapering with elevation. Between 1600 and 2000 m, the crust is punchy and unsupportive. In the lower snowpack, a crust/facet layer sits near the ground. The most recent avalanche observed on this layer was on December 1st, while recent snowpack tests in the Cayoosh zone found this layer down 60 cm and unreactive. We have a lot of uncertainty on the reactivity of this layer so we're keeping it on our radar. 

• Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
• Wind slabs are most reactive during their formation.
• A crust on the surface will help bind the snow together, but may make for tough travel conditions.