Avalanche Forecast
Issued: Dec 15th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
TH,
Avalanche Canada
Strong to Extreme southwest winds have generated some natural activity on the deep persistent layer and will remain elevated through Saturday.
Fresh wind slabs should be anticipated and can be expected to be sensitive to human traffic.
Travel remains poor BTL.
Days are short.
Practice conservative decision making.
Summary
Confidence
Moderate
Avalanche Summary
A large natural was observed today in the alpine on Mount Fairview. This was no likely a result of wind loading and failed next to the ground on the deep persistent layer.
Lake Louise ski patrol remote triggered a size 1.5 wind slab Thursday. The feature was at treeline and was a reloaded bed surface from a previous avalanche.
Snowpack Summary
Last week's storm snow has settled to 20-40cm at treeline. A rain crust up to 7cm thick exists within this storm snow as high as 2300 and has been found to be more extensive in the southern part of the region. Wind slabs are prevalent from previous strong winds.
This upper snow overlies the deep persistent weak layer that consists of surface hoar facets and depth hoar. Treeline snow depths range from 50-80cm.
Click here for the snow profile from Tuesday in the Dolomite peak area.
Weather Summary
SW alpine winds will increase into the extreme range Friday night.
Alpine temperature inversions look possible through to Monday morning as do trace amounts of snow.
Winds will shift W /NW and back off into the moderate range Sunday morning before shifting back SW and ramping right back up to strong range in the afternoon.
For more information, click Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.
Problems
Wind Slabs
SW winds increased to strong values Friday afternoon and are creating new wind slabs in alpine and exposed treeline terrain. New slab development will add to the existing wind slabs formed last week. These slabs will likely be sensitive to skiers in steep terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The bottom 1/4 to 1/2 of the snowpack is weak and consists of layers of surface hoar, facets, depth hoar, and occasionally, a crust . If initiated, larger avalanches can result which hold the potential to run further than expected and reach below treeline elevations.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 16th, 2023 4:00PM
