Avalanche Forecast
Regions: Bull, Crowsnest North, Crowsnest South, Elkford East, Elkford West, South Rockies.
Watch for pockets of fresh wind slab at ridgetop. Elsewhere, fresh snow covers older wind slabs which may remain reactive to rider triggers.
A buried weak layer looms in the west and central parts of the region. Check out our latest blog for ways of managing persistent avalanche problems.
Confidence
Moderate
Avalanche Summary
A natural size 1.5 persistent slab avalanche was observed southeast of Elkford on Tuesday. It is suspected to have run on a weak layer buried in November that has been showing results in snowpack tests as well as signs of instability like whumpfing and cracking. In neighboring regions to the west and south, where it is buried deeper, reports of rider-triggered avalanche activity on this layer have been prolific. Unfortunately, more likely than not, this is a sign of what is to come for the west and central parts of the region.
Otherwise, avalanche activity in the region has been limited to explosive triggered wind slabs size 1-2 in the east of the region.
Snowpack Summary
Even in the notoriously windy Crowsnest, 5-10 cm of soft new snow remains fairly evenly distributed except at very exposed ridgetops. It sits over previously formed wind slabs at most elevations. Buried surface hoar has been observed beneath these aging wind slabs in the east of the region, which may keep them reactive where it exists.
A weak layer consisting of facets and surface hoar formed in November is now buried 45-65 cm deep in the west and central parts of the region. In the east, it may exist as a crust on solar aspects. This layer has been producing large avalanches in neighboring regions and has shown reactivity in snowpack tests here. This one is definitely on our radar!
The lower snowpack consists of sugary and faceted snow, with a thick rain crust near the ground.
Total snowpack depths at treeline elevations are 75 to 155 cm.
Weather Summary
Wednesday night
Clear. Light northerly wind. Alpine low -15 C.
Thursday
Sunny. Light northerly wind. Alpine high -7 C.
Friday
Mostly sunny. Ridgetop wind increasing to strong northwest as a cold front passes through. Alpine high -9 C.
Saturday
Mostly cloudy with scattered flurries in wake of the cold front. Moderate westerly ridgetop wind. Alpine high -10 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Recent new snow may be hiding windslabs that were easily visible before the snow fell.
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Wind Slabs
Much of the region has been heavily wind affected by previous wind. Wind slabs may remain triggerable by riders at all elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 1.5
Persistent Slabs
A buried weak layer of surface hoar and facets exists 40-70 cm deep and is showing reactivity in snowpack tests. Avalanches on this layer are possible where overlying snow has formed a cohesive slab due to wind or settlement. This layer has not shown to be problematic in the Crowsnest area in the east of the region.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5