Avalanche Forecast
Issued: Feb 24th, 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.
zryan,
Avalanche Canada
Watch for changing conditions. As new snow and wind arrive on Saturday afternoon, fresh reactive wind slabs may form in exposed areas.
Triggering a deep persistent slab remains possible, especially in areas with a thin snowpack. Sheltered terrain will offer the best and safest riding.
Summary
Confidence
High
Avalanche Summary
On Thursday, two size 3 deep persistent slab avalanches were observed just north of the Hurley summit. These slabs are suspected to have failed within the last two days. One was on a north-facing alpine face and the other an exposed, east-facing open slope at treeline. A nearby operation was able to trigger two size 2 wind slabs with a snowcat groomer on northwest-facing terrain at treeline.
Also on Thursday, skiers were able to trigger small (size 1) wind slabs in alpine terrain on south to east aspects the Birkenhead north of Pemberton.
On Tuesday there were reports of a few size 2.5 naturally triggered windslab avalanches on northerly and southerly aspects in the alpine in the Birkenhead area and in the south Chilcotin.
Snowpack Summary
Previous northeasterly winds have redistributed recent storm snow and formed stiff wind slabs in exposed areas. In sheltered areas, surface faceting due to cold temperatures and/or soft surface snow remains.
A melt-freeze crust from late January can be found down 60-80 cm. At the moment this layer appears to be gaining strength though in isolated areas small facets can still be found above the crust.
There is a widespread weak layer of large sugary facets at the bottom of the snowpack. Recent avalanche activity on this layer has been confined to northern parts of the region in the Chilcotins. Snowpack depths around treeline range between 150 to 250 cm.
Weather Summary
Friday night
A mix of sun and cloud. Alpine temperatures around -16 °C. Light ridge wind. Freezing level at valley bottom.
Saturday
A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -8 °C. Ridge wind 20 km/h gusting to 50 km/h from the southwest. Freezing level at valley bottom.
Sunday
Mainly cloudy with scattered flurries, 5 cm accumulation. Alpine temperatures reach a high of -10 °C. Ridge wind southwest 20 km/h gusting to 50 km/h. Freezing level at valley bottom.
Monday
Sunny with cloudy periods. Alpine temperatures reach a high of -7 °C. Mostly light ridge wind occasionally gusting to 35 km/h. Freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be especially cautious as you transition into wind affected terrain.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Wind Slabs
Variable winds have redistributed recent storm snow into stiff pockets of wind slabs. Winds today will be from the southwest, whereas previous wind slabs formed in a reverse loading pattern due to northeast winds. Be sure to assess the snow surface on any aspect you are travelling on for clues of wind effect, like cracking or hollow drum-like sounds.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of weak facets sits near the base of the snowpack. This layer is most likely to be problematic in steep, unsupported, wind-loaded terrain in the northern part of the region around the Chilcotins, Birkenhead, and Hurley.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 25th, 2023 4:00PM
