Avalanche Forecast

Moderate - Uncertainty is due to the fact that deep persistent slabs are particularly difficult to forecast.

MONDAY NIGHT: Clear skies, light to moderate north wind, treeline temperatures around -1 C, freezing level around 1300 m.

TUESDAY: Increasing cloud and wind throughout the day as temperatures drop, sunny in the morning with light west wind and treeline temperature around -2 C then some light snowfall in the afternoon with strong southwest wind as treeline temperatures drop to -4 C.

WEDNESDAY: Mix of sun and cloud, light variable ridgetop wind, treeline temperatures around -5 C.

THURSDAY: Cloudy with some light flurries, light wind, treeline temperatures around -5 C.

A few small wind slab and wet loose avalanches were reported on Sunday and Monday. Explosive control targeting cornices on Friday and Saturday produced size 2 results, some triggering deep slabs on the rocky slopes below. 

There has been significant deep persistent slab activity this month. During a widespread avalanche cycle last week, several storm slabs stepped down to deeper weak layers resulting in very large (size 3-4) deep persistent slab avalanches (see these photos from Panorama Ridge). On Jan 9, a large (size 3) avalanche was remotely triggered by skiers on Cowboy Ridge near Whistler. The avalanche occurred on a north to northwest aspect at around 1900 m. The crown was up to 200 cm deep and was approximately 200 m wide. See this MIN for photos and more information. A similar avalanche was remotely triggered by skiers on a nearby westerly slope a few days before (see this MIN).

Ski quality in the extensively wind affected alpine has been widely referred to as chalky. Soft snow may be found in sheltered areas around treeline and may overlie a spotty layer of surface hoar. A widespread surface crust exists below 1900 m and on south-facing slopes.

The snowpack is currently quite complex. A layer of sugary faceted grains above a hard melt-freeze crust from early December may be found down 100 to 200 cm. Just over a week ago, several large natural and human-triggered avalanches on this layer occurred, with the hot spots being around the Whistler backcountry. Near the base of the snowpack, there may be faceted grains above a crust from early-November, which has also been identified as the failure layer in sporadic avalanche releases.

• Use ridges or ribs to avoid areas of wind loaded snow.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
• Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
• In times of uncertainty conservative terrain choices are our best defense.