Avalanche Forecast
Regions: Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Jasper, Maligne, Marmot, Miette Lake, Pyramid.
The new snow will make for great skiing but the snowpack is still adjusting to this change. Keep your eyes out for windslabs and carefully assess the potential for triggering the deeper instabilities.
Ice climbers, watch for solar-triggered dry loose avalanches in steep, rocky terrain if the sun breaks through.
Confidence
Moderate
Avalanche Summary
Avalanche control on Saturday, December 7th, produced wind slabs up to size 2 near Parkers Ridge.
At Marmot Basin, size 2 avalanches were observed late last week, failing on facets above the October 18 melt-freeze crust. These were triggered by large explosives in the alpine. This indicates that this layer is a problem in certain areas and can be triggered in the right— or rather, the wrong— locations.
Snowpack Summary
Up to 25cm of new snow sits on a thin melt freeze crust. Strong winds have redistributed this snow into windslabs that may fail on the crust or on deeper layers. Three weak layers exist in the snowpack; the Nov 8th crust and facets that are down 30-40 cm at tree-line and below, surface hoar that has been found down 70cm at 2500m and the October crust which is found near the base of the snow pack with facets above and below. Snow depth is roughly 70 cm at treeline and tapers rapidly below.
Weather Summary
Monday
A mix of sun and cloud. Alpine temperature High -11 °C. Ridge wind from the west (10 km/h). Freezing level at valley bottom.
Tuesday
A mix of sun and cloud. Alpine temperature Low -11 °C and High -7 °C. Ridge wind from the west (10 km/h). Freezing level at valley bottom.
Terrain and Travel Advice
- Be mindful that deep instabilities are still present in the snowpack.
- Be careful as you transition into wind-affected terrain.
Avalanche Problems
Deep Persistent Slabs
This problem includes the Oct 18 crust and the Nov 8th crust and surface hoar. These layers may wake up with the new load. Evaluate carefully as these layers are getting buried deeper and deeper and will take some diligent investigation.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2.5
Wind Slabs
The new snow from the weekend arrived with high winds that created windslabs in leeward features. Avoid wind loaded pockets and evaluate carefully before entering steep and unsupported terrain that could be affected by wind.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2