Avalanche Forecast
Issued: Apr 3rd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
MBender,
Avalanche Canada
It seems like it is still winter and the snow keeps coming steadily. Expect to see a bit of new snow accumulate through the end of the weekend along with wind blowing from the southwest then northwest. Wind slabs at upper elevations are the main concern.
Summary
Confidence
Weather Forecast
Saturday Night: Mostly cloudy with scattered flurries, accumulation 3-10 cm. Light to moderate southwest wind. Freezing level 500 m. Alpine temperature -7.
Sunday: Partly cloudy with scattered flurries, accumulation 3-5 cm. Moderate southwest switching to northwest wind. Freezing level 1400 m. Alpine temperature -4.
Monday: Mostly cloudy. Moderate southwest wind. Freezing level 1700 m. Alpine temperature -2.
Tuesday: Cloudy with isolated flurries. Light to moderate southwest wind. Freezing level 1400 m. Alpine temperature -4.
Avalanche Summary
There are no recent reports of avalanche activity, although with recent snow and wind there is likely natural wind slab activity at upper elevations.
Evidence of large storm slab avalanches (size 3) was observed Monday and Tuesday between Sentinel Pass and Chetwynd, likely having released during the storm on the weekend.
Snowpack Summary
10-40 cm of recent snow earlier in the week has been redistributed by strong southwest to northwest wind with wind slabs possible on many aspects and large, fragile cornices along ridgetops. This snow sits on melt freeze crusts at lower elevations and on solar aspects.
A weak layer of facets buried in mid-February may now be found around 120 to 150 cm deep, or shallower in the east of the region and in thin snowpack areas. The most likely place to trigger this layer is where the snowpack is shallow in alpine terrain. Large loads, such a cornice falls or multiple sleds on the same slope often trigger slopes that a single rider couldn't trigger on their own.
Terrain and Travel
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Be aware of highly variable recent wind loading patterns.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Wind Slabs
Flurries bringing small amounts of new snow will feed fresh wind slab development. Variable wind direction has resulted in deep pockets of recent storm snow on a variety of aspects. These older wind slabs are likely becoming more difficult to trigger.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
The persistent slab problem is most likely on the eastern slopes of the region (e.g., Kakwa, Tumbler Ridge) and in areas where the snowpack is thin. Steep, rocky slopes with a shallow or thin to thick snowpack in the alpine are the most likely places to trigger buried weak layers. This problem likely won't go away until a substantial melt-freeze cycling occurs.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 5th, 2021 4:00PM
