Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
Residual windslabs remain on lee alpine features. Despite the improvement in travel, the unpredictable nature of the very weak snow at the bottom of the snowpack inspires little confidence. Keep to terrain choices where large steep features can be avoided.
Days are short: aim to be back to the trailhead by about 4 PM
Confidence
Moderate
Avalanche Summary
Whumpfing is still being reported from alpine areas (Dolomite Circuit, Hector shoulder). We suspect this is occurring on the weak basal layer.
Ski hill snow safety teams reported only a few, 10-20cm deep, wind slabs that were observed local to their explosive shots Thursday & Friday in alpine features.
Snowpack Summary
Recent SW winds created some wind slabs in alpine. There may be a new surface crust up to 2000 m from the past few unseasonably warm days.
The mid-pack is generally carrying skis right now (not boots) with ski penetrations of 5-10 cm. In southern parts of the region, there is a mid-pack rain crust that is up to 7 cm thick and has been observed as high as 2300m. It is not as high in northern areas.
The lower snowpack is facetted and very weak.
Treeline snowpack depths range from 50-95cm.
Weather Summary
Temperatures drop tonight with alpine lows reaching -18C as a cold front descends. Expect to see a few flurries Friday night followed by a clearing trend on Saturday with light westerly winds.
Temperatures will continue to drop through Saturday, with lows -20C and highs around -12C for Sunday and Christmas day.
For more information, click Mountain Weather Forecast.
Terrain and Travel Advice
- Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.
Avalanche Problems
Wind Slabs
SW winds have created thin wind slabs in alpine over the past few days that have been triggered by explosive work by ski hill snow safety teams and some ski cuts. If this problem is triggered, it could step down to the deep persistent layer at the bottom of the snowpack.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 1 - 1.5
Deep Persistent Slabs
The bottom layers of the snowpack are facetted and weak. Human triggering remains possible and could result in a large avalanche. Given the unpredictable nature of this problem, it leaves little inspiration for venturing on to any steeper slope with consequence.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 2.5