Avalanche Forecast
Regions: Glacier.
Sunshine on Wednesday will play a major role in natural avalanches on S'ly aspects.
Expect avalanche activity to follow the arc of the sun, peaking when direct sun bakes the slopes.
Weather Forecast
Clearing Wed, then a dramatic warming Thurs with sun and cloud to mimic the greenhouse effect.
Tonight: Clearing, trace to 5cm, Alp low -10*C, FZL 500m, gusty mod W winds
Wed: Sun and cloud, Alp high -5*C, FZL 1500m, light SW winds
Thurs: Sun and cloud, Alp high 2*C, FZL 2800m, mod SW winds
Fri: Flurries, 6cm, Alp high 1*C, FZL 2100m, strong SW winds
Snowpack Summary
50-70cm of snow in the last 4 days at Treeline and above has buried a variety of surfaces (wind slabs, solar crusts to mtn top, and a melt/freeze crust to 2200m). Slopes in the Alpine hold cold, wintery snow, deeper on N'ly aspects. The December 1st crust is down 1.5-2m. Late season cornices are LARGE, with fresh, fragile new lobes recently added.
Avalanche Summary
A field team in the west end of the park easily ski cut a sz 2 persistent slab, 70cm deep, 50m wide, NE aspect, at 2150m.
Artillery control on Mon produced slab avalanches up to sz 3-3.5, N aspects being most reactive to explosives.
Nearest neighbours report easy triggering of the new wind/persistent slab between 2000-2200m on slopes >35*.
Confidence
Timing or intensity of solar radiation is uncertain
Avalanche Problems
Persistent Slabs
New storm snow (70cm in the west, 50cm in the east) overlies a firm crust at treeline and above. Direct observations and reports from nearest neighbours indicate a poor bond to the underlying bed surface.
- The storm slab may be more sensitive to human triggering on solar aspects where it sits on sun crust
- Use caution in lee and cross-loaded terrain near ridge crests.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5
Wind Slabs
Moderate to strong SW winds are redistributing the new snow into Alpine and Treeline lee features. Be suspect of slopes where stiffer, dense surface slabs are present; these slabs are ripe for human triggering.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2.5