Avalanche Forecast
Regions: Glacier.
Energy in the upper snowpack is building as the new snow buries the surface hoar deeper with every falling crystal. The storm slab will likely be responsive to human presence, triggering easily.
Weather Forecast
So far we have received 20cm, more snow than forecasted, with another 10-20cm by Monday morning. Monday will be cloudy with flurries throughout the day, 20-40km/hr West winds and an Alpine high of -10. Clearing on Tuesday night and the return of cold temperatures (-25) into Wednesday.
Snowpack Summary
20+cm now buries the Jan 29 surface hoar (5-15mm) and crusts on steep solar aspects. Expect to find storm slab at all elevations, but will be deeper in wind deposited areas in the alpine and at tree line. The Jan 20 surface hoar (2-4mm) is down 35cm. The Dec 1 crust/facet combo is down 1.5 - 2.5m.
Avalanche Summary
Avalanche Control is planned overnight on Sunday into Monday when avalanche activity will be at its height.
We are expecting an avalanche cycle to occur, failing on the Jan 29 surface hoar layer and potentially stepping down to deeper layers. This layer exists at all elevations in sheltered / shaded areas and will likely persist for awhile.
Confidence
Intensity of incoming weather systems is uncertain on Monday
Avalanche Problems
Storm Slabs
20+cm of new snow and moderate Westerly winds have buried the Jan 29 surface hoar (5-15mm), a crust on steep solar aspects and hard surfaces everywhere else. It is likely this layer will be easy to trigger and could step down to deeper layers.
- Use caution on open slopes and convex rolls where buried surface hoar may be preserved.
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 3
Loose Dry
The new snow has buried the Jan 29 surface hoar (5-15mm) and will likely be easy to trigger, especially in steeper terrain and on roll overs. Manage your sluff appropriately, watching out for people above and below you.
- Be careful of loose dry power sluffing in steep, confined or exposed terrain.
- Use caution above cliffs and terrain traps where small avalanches may have severe consequences.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2
Persistent Slabs
There are several surface hoar layers in the upper snowpack that may wake up with the new snow load. If triggered it has the potential to step down to the even deeper Dec 1 crust/facet layer, resulting in a very large avalanche.
- Avoid steep convexities or areas with a thin or variable snowpack
- Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3