Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
A significant storm will start Sunday night and last until Tuesday with rain below 2000m, up to 40cm of snow up high and strong winds. It will be a good time to avoid exposure to avalanche terrain.
Confidence
Moderate
Avalanche Summary
Sunshine had minimal results (size 1-1.5) windslabs with explosives and a size 1 ski cut deep persistent slab. No other avalanches observed or reported.
Snowpack Summary
Up to 5cm of new snow sits over sun crusts on solar aspects. Isolated small wind slabs in the alpine.
A weak, isothermal snowpack is developing BTL with minimal overnight recovery.
Several buried crusts can be found in the top 40cm on solar aspects.
The January sun crust and facet interface is down 40 to 80cm.
The November depth hoar at the base of the snowpack remains very weak.
Weather Summary
Sunday night: 10-15cm of snow above 2000m and rain below with Strong SW winds in the alp.
Monday: 10-15cm of snow above 2000-2300m with rain below and strong sw winds which will diminish through the day.
Tuesday: 5-10cm of snow with cooler temperatures and freezing levels 1500-1800m.
For a detailed forecast click here.
Avalanche Problems
Deep Persistent Slabs
The November basal facets as well as midpack facets on crusts remain a concern for triggering. The new load will be a big test, likely increasing the chance of large avalanches, some of which could reach valley bottoms.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 2 - 3.5
Storm Slabs
Snow should start at around treeline Sunday night through Tuesday. Storm slabs will likely develop with an increased chance of natural and human-triggered avalanches on various aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2
Loose Wet
Rain is probable below 2000m, and warm, wet snow above this. Wet avalanches are almost certain during this period.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely - Certain
Expected Size: 1 - 2