Avalanche Forecast

Moderate - Uncertainty is due to whether buried persistent weak layers become active, triggering avalanches, with the arrival of the forecast weather. Forecast precipitation (either snow or rain) amounts are uncertain.

Monday Night: 5-15 cm expected overnight. Alpine temperatures near -1 and ridgetop wind strong from the southwest. Freezing levels 1000 m.

Tuesday: 5-20 cm and alpine temperatures near -2. Ridgetop wind will be strong from the southwest. Freezing levels 900 m.

Wednesday: 5-10 cm and alpine temperatures near -5. Ridgetop wind will be strong southwest. Freezing levels 700 m.

Thursday: Some flurries up to 5 cm. Alpine temperatures near -5 with freezing levels falling to 660 m. Cranking southwest wind is forecast.

On Monday, a natural cornice fall size 2 was reported. This only pulled a slab avalanche within the recent storm snow and did not step down deeper to suspect weak layers. Natural avalanche activity will likely continue with the storm on Tuesday. 

Over the weekend, observers reported a natural storm slab avalanche cycle (size 2-3). One storm slab reportedly released from a corniced alpine ridge feature. Additionally, numerous small to large (size 1-2) wet loose avalanches were observed on all aspects and up to alpine elevations during peak warming.

Areas near Ningunsaw continue to see large to very large deep persistent slab avalanches (size 2-3.5) releasing on weak snow at the ground. 

Last week, operators near Bear Pass reported natural and explosive triggered avalanches releasing on the early November facet/crust later. Easy-to-trigger storm slab avalanches have the potential to step-down to these deeper layers and produce large, destructive avalanches.

Have you been out riding in the mountains? We would love to hear about it and it doesn't need to be technical! Photos can be extremely helpful, please share your observations on the Mountain Information Network (MIN). Thanks!!

As of Monday morning, weekend storm totals ranged from 55-95 mm of water in 62 hours and above freezing temperatures up to 1900 m and now dropping. At summit elevations and in areas further north in the region, precipitation fell as snow and some operators are reporting up 90 cm throughout this stormy period. Strong winds from the south have rapidly loaded areas receiving snow with touchy storm slabs. More snow and strong southwest wind will continue to build these storm slabs over the next few days. Cornices may also become overloaded and weak. Below the freezing level, the snowpack is saturated at this point but may start to freeze into a crust as the freezing level drops.

The intense periods of precipitation has the potential to bring buried weak layers to their breaking point. Two early season weak layers are still on our radar: a facet/crust combination that formed in early November and a layer of facets near the ground. In the Ningunsaw area, basal facets have recently produced very large deep persistent slab avalanches. The early November crust also been reactive in the Bear Pass area within the last week. The extent of this problematic snowpack structure in the region is not well-known, but it likely exists in colder, shallower snowpack areas.

Snowpack depths are highly variable across aspects and elevations as a product of wind scouring, above-freezing temperatures, and rain. Snow has melted fast at lower elevations, and snowpack depths have seen rapid settlement.

• Avoid the alpine during periods of heavy loading from new snow wind and/or rain.
• Avoid exposure to overhead avalanche terrain during periods of heavy loading from new snow, wind or rain.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.
• A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.