Avalanche Forecast

Wednesday night: Increasing cloud. Light NW wind switching SW. Treeline temperature around -22 °C. 

Thursday: Light snowfall 3-6 cm. Moderate SW wind. Treeline high around -14 °C. 

Friday: Snowfall 5-10 cm. Moderate to strong SW wind. Treeline high around -4 °C.

Saturday: Snowfall tapering 5-10 cm. Moderate SW wind. Treeline high around -10 °C. 

On Monday and Tuesday, natural storm slabs and loose dry avalanches size 1-2 were observed out of NE-SE aspects in the alpine. Explosive triggered storm slabs were observed up to size 2 and ski cut up to size 1.

The persistent slab problem continues to produce sporadic and spotty activity in the South Rockies and nearby regions.

• On Tuesday just east of the region in the Rockies near Invermere, a size 3.5 (very large) persistent slab avalanche was triggered remotely by a skier on an alpine ridgetop. The resulting crown was 2-3 m deep and the avalanche ran about 1 km to the valley bottom. More details in this MIN report. This and other notable persistent slab avalanches in neighboring regions feature in our latest blog, Photos of recent persistent slab avalanches in the southern interior.

• On last Friday, explosives triggered a size 2.5 wind slab avalanche that stepped down to the persistent slab layer on a SE aspect near treeline. While recent reports of large persistent slab avalanches have been minimal in the region, neighbouring regions including the Lizard-Flathead have seen some concerning avalanches recently including this one on Sunday.

The region typically received 20-30 cm of new snow from the recent storm. This new storm snow buried a highly wind affected snow surface and widespread facets from the recent cold conditions which may create a weak bond with the new snow. The new snowfall was accompanied by moderate to strong winds at higher elevations and the new storm slabs are expected to be most reactive in wind loaded areas in the alpine. 

The most notable layer of concern in the snowpack is a crust that was formed in early December and is now typically down 70-130 cm. In the past week, we have seen explosive triggered activity on this layer as well as snowpack tests that have shown that the layer remains reactive. Neighbouring regions have seen very large avalanches on this layer over the past week. This layer has created a low likelihood, high consequence scenario which is best managed through conservative terrain choices and disciplined backcountry travel techniques. 

• Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
• Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
• Be aware of the potential for large avalanches due to the presence of a persistent slab.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.