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.
IJ,
Avalanche Canada
Avalanche control is planned for Mt Bourgeau and Eagle Mountain on the Sunshine Village Access road on Wednesday December 28th. No access to these areas on Dec. 28th. Click here for a description of the area, and maps.
Summary
Confidence
Moderate
Avalanche Summary
The snow safety team at the Lake Louise Ski Resort triggered several size 2 avalanches today in steep alpine terrain. These were 25-60 cm deep windslabs and were triggered by a mixture of ski cuts, skiier remotes and explosives. At least one occurred on a reloaded bed surface. At treeline, things were cracking and whumphing but the slabs being triggered were much smaller and softer.
Snowpack Summary
Strong westerly winds that occurred over the weekend have blown 20-30 cm of recent snow into widespread windslabs in the alpine and some treeline areas. These slabs sit atop a weak layer of facets and surface hoar (Dec. 17th interface) and have been producing skiier triggered avalanches to size 2. Below this, the snowpack is generally facetted with the largest facets and depth hoar near the bottom.
Snowpack depths at treeline range from 80-140 cm throughout the region. Snow profile at Pulpit from Tuesday here.
Weather Summary
A final low pressure system and associated cold front is moving through on Wednesday before drier and colder conditions arrive.
Wednesday: Temperatures at treeline -3 to -5. Alpine winds light to moderate from the SW and 2-5cm snow.
Thursday: Temperatures at treeline ~ -7 and cooling to -10 by end of day. Alpine winds light to moderate from the SW. 1-2 cm in the AM and clearing in the afternoon
Friday: Temperatures at treeline -5 to -10. Alpine winds light to moderate from the SW. Trace of new snow.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Wind Slabs
Fresh windslabs exist in the alpine and exposed treeline locations. These slabs overlie weak, faceted snow that was on the surface during the prolonged deep freeze and human triggering is likely in many locations.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The whole snowpack is thin, weak and faceted, meaning that any avalanche starting in the upper layers could easily release on the ground. Avoid large alpine open slopes >30 degrees, especially where shallow and windswept and don't linger any longer than neccessary under overhead hazard.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
The snowpack below treeline is comprised almost entirely of weak, unconsolidated facets that sluff easily in very steep terrain. Steep gullies or chutes below treeline could develop larger than-expected sluffs, running further and with more force than usual. This problem is most prominent in thinner snowpack zones.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Dec 28th, 2022 4:00PM
