Avalanche Forecast
Regions: Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Jasper, Maligne, Marmot, Miette Lake, Pyramid.
The avalanche hazard is expected to rise over the weekend with the incoming warm temperatures.
Watch for signs of instability, especially snowballing and loose wet avalanches, that indicate the rising temperatures are effecting the snowpack, and the possibility of Deep Persistent Avalanches is increasing.
Confidence
Moderate
Avalanche Summary
Marmot Basin has reported a few explosive triggered large deep persistent slabs in the alpine on north aspect. Parkway patrol did not observe any new natural avalanche activity on Thursday. A few small loose wet slides have been observed along the Maligne Road on solar aspects, in steep rocky terrain below the tree line.
Snowpack Summary
The snowpack continues to be weak and largely unsupportive, though recent storm snow has improved travel. HS at tree-line is 45-75cm. Ski penetration is down ~30cm which shows that there is some structure (slab) in the mid-pack. An interface down ~25cm shows up in snowpack tests; while in the field, reactivity will be subject to the strength of the slab over the PWL layer. Expect temperature crusts at lower elevations as freezing levels rise above valley bottom.
Weather Summary
Unseasonably warm conditions will begin to move into the area on Saturday, with freezing levels rising to between 1600 and 1800m.
The Mountain Weather Forecast is available at Avalanche Canada https://avalanche.ca/weather/forecast
Terrain and Travel Advice
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Avalanche Problems
Deep Persistent Slabs
The base of the snowpack is inherently weak and untrustworthy. Concern for human and natural triggering of this avalanche problem will increase as the temperatures rise over the next few days.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2 - 3
Persistent Slabs
Recent reported avalanches in the Icefields were down ~30cm on this suspect interface. This layer is concerning when there is a cohesive slab overlying it. Watch for the warnings in the snowpack like shooting cracks.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Loose Wet
Watch for this problem to become more significant as the temperatures rise, particularly in steep and rocky terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 1.5