Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
Solar heating will again be the dominant weather input Monday however heating may have peaked Sunday.
Solar and human-triggered avalanches remain possible.
Conditions are set to change dramatically Tuesday.
Through these fluctuating heating conditions, we will list the highest expected rating of the day.
Confidence
Moderate
Avalanche Summary
A natural avalanche cycle continued today with the field team reporting fresh avalanches from the past 24hrs near the Lake Louise Ski Area. Avalanches up to size 3.5 on all aspects and at all elevations have been observed over the last 3 days. Human remote triggering of the persistent and deep persistent layers also continues as people venture near avalanche terrain.
Snowpack Summary
Moist snow up to 2600m on all aspects and as higher on solar aspects with daytime heating. Crust formation during the evening depending on freezing levels. Only high north aspects hold dry snow. 40-90 cm of settled snow overlies weaker facets above the Feb 3 interface which is a crust up to at least 2500 m. The base of the snowpack consists of weak facets. Deeper snowpack areas (west of the divide) are more settled and dense.
Weather Summary
Sunday Night: Below freezing in the valley bottoms with an AFL from 2300m to 2700m. Winds light to moderate westerly.
Monday: Freezing levels rise to 2800m with winds remaining light to moderate.
Tuesday: As the day starts, freezing levels will climb to near 2000m, then a cold front arrives with increasing clouds, cooling, and snow into the afternoon. Winds SW light.
For more details on the weather, click here.
Terrain and Travel Advice
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
Avalanche Problems
Persistent Slabs
40-90cm of settled snow and soft slab overlies weak facets on the Feb 3 interface, which is a crust in most areas. Many natural, human, and explosive-triggered avalanches have occurred on this layer with remote triggering observed in many instances.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3
Deep Persistent Slabs
Many recent avalanches have stepped down to the weak facet and depth hoar layers near the base of the snowpack resulting in large avalanches. This seems to be most common in thin, steep, rocky terrain in the alpine.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 2 - 3.5
Loose Wet
The sun's effect and overall higher freezing levels will be lower on Monday with the peak of our current warming event observed on the weekend however, the likelihood of wet loose avalanches will increase as the day goes on, especially on solar aspects and from rocky outcrops.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2