Avalanche Forecast

Moderate - Uncertainty is due to the limited number of field observations.

Thursday Night: Mostly clear. Moderate to strong northwest winds. Treeline high around -20 °C.

Friday: A mix of sun and cloud. Strong southwest winds, trending to moderate west at higher elevations. Treeline high around -18 °C. Possible temperature inversion could result in temperatures above -10 °C at 2500m. 

Saturday: Mostly cloudy. 2-10 cm of snow expected. Moderate to strong south winds. Treeline high around -14 °C. 

Sunday: Cloudy in the morning, clearing off through the day. 3-9 cm of snow expected overnight, and a possible trace through the day. Strong northeast winds with the possibility for higher winds at lower elevations. 

Wind slabs formed on all aspects in exposed terrain are expected to remain sensitive to human triggers.

No new avalanches were reported on Tuesday or Wednesday. 

On Monday, a natural wind slab avalanche cycle up to size 2.5 was reported on SW-W aspects near Pine Pass in response to strong NE-E winds. 

Given the variable nature of the recent wind, slabs should be expected on all aspects in exposed terrain. 

On Thursday, the wind shifted to the northwest so new wind slab formation on south and east aspects is expected where there is still unconsolidated surface snow available for transport. 

Check out this post from the Mountain Information Network (MIN) by our North Rockies field team for a great summary of conditions in Torpy on Thursday, and this post for Pine Bowl on Wednesday.

On Friday and Saturday, 20-30 cm of new snow was reported along with strong winds from the southwest which formed highly reactive slabs in wind exposed terrain, primarily on north and east aspects. On Monday, the wind switched directions and formed wind slabs on south and west aspects. 

The mid and lower snowpack likely contains of a series of early season crusts which may had undergone some faceting. In the deeper snowpack areas of the region, these layers generally appear to have stabilized and gone dormant but they still may be reactive in isolated areas, especially places with a shallow snowpack. Below around 1500 m elevation, the late-November crust is typically found down around 40 cm but generally appears to be unreactive.

Snowpack depth at treeline typically ranges from 50-250 cm, with the shallower value mainly on the eastern side of the range. The alpine snowpack typically ranges from 150-250 cm. 

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Recent wind has varied in direction so watch for wind slabs on all aspects.
• Be alert to conditions that change with elevation and wind exposure.