Avalanche Forecast
Issued: Dec 17th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
trettie,
Avalanche Canada
Be aware that if triggered, avalanches may step down to deeper layers resulting in large, destructive avalanches. Keep your terrain choices conservative, as temperatures fall even a small accident can have big consequences.
Summary
Confidence
Avalanche Summary
On Friday large avalanches were triggered using explosives on north facing rtreeline features.
On Thursday Several size 2 natural avalanches were observed in treeline terrain in the Elkford area. These avalanches likely occured earlier in the week and failed on the mid November surface hoar layer which is down around 40 in this area.
Persistent slab avalanche activity has continued to taper off throughout the week but these layers will likely remain triggerable in specific terrain features.
Snowpack Summary
around 15cm of recent low density snow overlies a thin sun crust on steep south slopes and surface hoar and facets in sheltered terrain. If winds pick up this low density snow will likely be redistributed into wind slab.
A well settled upper snowpack may overlie a spoty layer of surface hoar and a thin sun crust formed in early December, now buried 30-50 cm deep. The mid November layer consisting of facets and surface hoar is now buried around 80cm deep. How ever both these layers can be found much shallower in the northern part of this forecast region. At the bottom of the snowpack, a thick crust sits on the ground.
At treeline, snowpack depths vary from 100 to 200 cm.
Weather Summary
Saturday Night
Mostly cloudy with flurries bringing 10 to 20cm of low density new snow. Light to moderate southwest wind. low of -19 at 1800m.
Sunday
Mostly cloudy with flurries bringing up to 5cm of new snow. Light to moderate southwest wind. High of -18 at 1800m.
Monday
A mix of sun and cloud with light flurries bringing trace amounts of new snow. Moderate west winds and a high of -20 at 1800m.
Tuesday
A mix of sun and cloud with light flurries bringing trace amounts of new snow. Moderate west winds and a high of -21 at 1800m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Avoid open slopes and convex rolls at and below treeline where weak layers may be preserved.
- In times of uncertainty conservative terrain choices are our best defense.
Problems
Wind Slabs
Winds have been variable meaning that wind slab could be found on all aspects in exposed terrain at treeline and above. These wind slabs could be more sensitive to rider triggering where they overlie a crust, facets or surface hoar.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Two persistent weak layers can be found in the top meter of the snowpack. The first is a surface hoar/crust layer from early December and the second is a surface hoar, facet or crust layer from mid November. The most recent activity on these layers has been in the northern part of the forecast region. These layers are most concerning on sheltered treeline features where surface hoar is most likely to be preserved.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 18th, 2022 4:00PM
