Avalanche Forecast
Issued: Dec 26th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Deep Persistent Slabs and Loose Dry.
TT,
Avalanche Canada
Up to 30 cm of new snow in combination with strong winds and a warm temperatures are a true test of our weak, faceted, snowpack. When adventuring during this holiday season, be very mindful of these changes and choose your ski lines conservatively.
Check AB511 for live updates on road closures.
Summary
Confidence
Moderate
Avalanche Summary
Minimal field observations on Monday due to Icefields Parkway closure. Snowballing observed at low elevation avalanche paths along Maligne road.
Few natural small loose dry avalanches have been observed below tree line along the Icefields Parkway corridor on Sunday.Marmot Basin reported several small stiff wind slab avalanches with good propagation on Sunday.
Snowpack Summary
Snowline was at approximately 1800m on Monday. Snowpack below 1800m had moist snow in the top 3- 5 cm. Up to 35 cm of snow has accumulated since December 23rd sitting over a faceted upper snowpack. Strong southwesterly winds creating hard wind slabs in the alpine and tree line. The bottom of the snowpack is weak and consisting of basal facets with pockets of depth hoar. Snow height ranges from 50-120cm.
Weather Summary
TuesdayFlurries.Accumulation: 8 cm.Alpine temperature: High -2 °C.Ridge wind southwest: 10-30 km/h.Freezing level: 1800 metres.
WednesdayCloudy with sunny periods and isolated flurries.Precipitation: Trace.Alpine temperature: Low -10 °C, High -4 °C.Ridge wind west: 15-30 km/h.Freezing level: 1500 metres.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
Problems
Wind Slabs
New snow and intense wind transport have created fresh winds slabs in the alpine and on exposed features at lower elevations. Incremental loading from this building wind slab problem is the first significant test of our weak faceted snowpack. If triggered, wind slabs may step down to our deep persistent slab resulting in large avalanches.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
This problem includes our prominent facet surface hoar layer down 30-40cm. The lower snow pack is weak and faceted which may cause avalanches initiating in the mid or upper snowpack to step down to the "deep" layer on or near the ground.
This problem may extend below tree line hazard in isolated, steep, open, slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Heavily faceted snowpack now has up to 30 cm of snow to overload it. Steep and shallow slopes are of most concern. Ice climbers should watch out for rocky ledges as the snow may gather volume and momentum on its way down the mountain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 27th, 2022 4:00PM
