Avalanche Forecast
Regions: Birkenhead, Duffey, South Chilcotin, South Coast Inland, Stein, Taseko.
Avoid all avalanche terrain during periods of high hazard.
Rain and high freezing levels can trigger avalanches on buried weak layers.
Confidence
Moderate
Avalanche Summary
On Monday, numerous natural and human triggered avalanches occurred up to size 2. These were wet and slab avalanches.
Saturday, a very large persistent slab avalanche was snowmobile triggered near Wendy Thompson. Cornice fall in the Chilcotins also triggered a size 2.5 storm slab on a slope below.
We expect avalanches to continue with wet and large slab avalanches being easy to trigger during this warm period.
Snowpack Summary
10 to 15 cm of new snow has been redistributed into deeper deposits on north- and east-facing slopes by moderate to strong southwesterly winds. Below treeline, this fell as rain so expect to find moist surface snow. Continued warm tempertures will moisten surfaces at all elevations.
A melt-freeze crust on southerly slopes up to 2000 m exists about 60 cm deep. This sits over 80 to 150 cm of settled snow.
The early March weak layer of facets or surface hoar on a crust is now down 100 to 170 cm and is present on all aspects except high north-facing slopes. Very large avalanches (size 3 to 3.5) were reported on this layer this past week.
Weak layers formed in mid-February and late-January are now buried 180 to 250 cm deep.
Weather Summary
Tuesday Night
Cloudy. 15 to 45 km/h south ridgetop winds. Treeline temperature 2 °C. Freezing level 1600 m.
Wednesday
Mostly cloudy with light rain. 15 to 20 km/h south ridgetop winds. Treeline temperature 9 °C. Freezing level rises to 3100 m.
Thursday
Cloudy with snow 5 to 10 cm. 15 to 35 km/h southwest ridgetop winds. Treeline temperature 2 °C. Freezing level 1900 m.
Friday
Cloudy with snow 5 to 10 cm. 15 gusting to 35 km/h southeast ridgetop winds. Treeline temperature 2 °C. Freezing level 1900 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Only the most simple non-avalanche terrain with no overhead hazard is appropriate at this time.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- Use extra caution for areas that are experiencing rapidly warming temperatures for the first time.
- Loose avalanches may step down to deeper layers, resulting in larger avalanches.
Avalanche Problems
Persistent Slabs
Weak layers remain a concern, especially in north-facing terrain where snowpack depth is variable. Avoid steep and shallow rocky features where human-triggering is possible.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1.5 - 3.5
Storm Slabs
Storm snow and strong southwest winds have formed reactive storm slabs. Expect to find deeper and more reactive deposits on north- and east-facing slopes.
Storm slabs may step-down to deeper layers resulting in very large avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Loose Wet
Rain-on-snow and warm temperatures can rapidly destabilize the snowpack.
Wet loose avalanches can trigger slab avalanches that fail on deeper snow or weak layers.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Likely
Expected Size: 1 - 2