Avalanche Forecast
Issued: Dec 27th, 2020 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Dry, Persistent Slabs and Wind Slabs.
Kate Ryan,
Assess your line before committing.
We currently have a complex snowpack with persistent weak layers in the low probability/ high consequence bubble.
There is a Special Avalanche Warning in effect. Click Here to access.
Summary
Weather Forecast
A ridge of high pressure will begin to build over BC today.
Weather is expected to remain consistent through tomorrow afternoon: cloudy with sunny periods and isolated flurries (trace). Light SW winds. Alpine temps steady around -9 C.
Snowpack Summary
Windslabs exist on ridge crests and exposed areas in the alpine and at treeline. In sheltered areas, the upper meter of the snowpack is generally 'right side up'. Weak layers: Dec 13 surface hoar/facets are down 70-110cm, Dec 7 crust/surface hoar layer is down 110-130cm+. The Nov 5 crust lingers near the base of the snowpack.
Avalanche Summary
Small natural and skier triggered loose dry avalanches occurred yesterday on steeper, open slopes on all aspects and elevations.
Thursday, a skier accidental size 2 slab avalanche occurred in a SE Couloir on Mt Afton.
Confidence
Problems
Loose Dry
Slough management is necessary on steeper, open slopes. Initiated loose dry slides are gathering enough mass to push a skier or rider over, or even bury one in a terrain trap. Manage your group carefully to enjoy the new snow!
- Be careful of loose dry power sluffing in steep terrain.
- If triggered dry loose point releases can form deeper deposits in terrain traps.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The Dec 7th surface hoar/crust and Dec 13th surface hoar layers have produced very large avalanches this past week, up to size 4! Although low in probability, the consequences are very high.
- Be aware of the potential for wide propagations.
- Avoid thin, rocky or unsupported slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Windslabs have formed on all aspects this past week due to SW flow during the storm and reverse N'ly winds after. These windslabs are likely loosing their sensitivity, however some reactive pockets may linger in isolated locations near ridge crests.
- Keep an eye out for reverse loading created by N-NE winds earlier in the week.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 28th, 2020 8:00AM
