Avalanche Forecast
Issued: Dec 16th, 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 and be prepared to back off quickly if you find signs of instability like whumpfing and shooting cracks.
Summary
Confidence
Moderate
Avalanche Summary
On Thursday Several size 2 natural avalanches were observed in treeline terrain in the Elkford area. These avalanches likely failed on the mid November surface hoar layer which is down around 40 in this area.
Last weekend, there were several alarming reports of large (size 2-3) persistent slab avalanches. They were remotely triggered by skiers or snowmobiles at treeline elevations. Check out these MIN reports here and here. A huge thank you to the groups who shared their observations to the Mountain Information Network!
Snowpack Summary
around 10cm of recent snow overlies a thin sun crust on steep south slopes and surface hoar and facets in sheltered terrain. Northwest winds will likely have redistributed snow onto south and east slopes and cross loaded others.
A well settled upper snowpack may overlie a layer of surface hoar formed in early December, now buried 30-50 cm deep. The mid November layer consisting of facets and surface hoar is now buried 70-90 cm 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 120 to 200 cm.
Weather Summary
Friday Night
Cloudy with the possibility of flurries bringing up to 5cm of new snow. Moderate to strong northwest ridge top winds shifting to west in the morning with a low of -14 at 1800m.
Saturday
Mostly cloudy with flurries bringing up to 10cm of new snow. Light to moderate westerly wind. High of -12 at 1800m.
Sunday
Mostly cloudy with flurries bringing up to 5cm of new snow. Moderate southwest wind. High of -18 at 1800m.
Monday
Mostly cloudy with light flurries bringing trace amounts of new snow. Moderate southwest winds and a high of -20 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
As ridgetop winds pick up from the northwest, watch for fresh wind slabs forming in atypical terrain features due to reverse-loading.
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 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 17th, 2022 4:00PM
