Avalanche Forecast
Issued: Feb 25th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
lbaker,
Avalanche Canada
Dangerous avalanche conditions exist where new snow and wind continue to add load above buried weak layers.
Uncertainty is best managed through conservative terrain choices at this time.
Summary
Confidence
Avalanche Summary
On Sunday, operators reported signs of instability such as shooting cracks and snow pillows failing on the persistent weak layer. Poor visibility means observations at higher elevations were limited.
On Saturday, skier triggered wind slab avalanches were reported to size 1.5. A skier accidental persistent slab avalanche was reported on a west aspect at 1900 m. The avalanche happened on a steep treeline feature and failed on surface hoar above the February 1 crust.
Snowpack Summary
5 to 15 cm of storm snow and strong westerly winds have created fresh wind slabs in open areas at treeline and above. Recent snow overlies a variety of surfaces including a crust on south facing slopes, wind affected surfaces in open areas and faceted surfaces in sheltered areas.
Roughly 40 to 60 cm down is a widespread crust with a weak layer of facets or isolated surface hoar above this crust. This problematic layering remains a concern with recent avalanche activity and snowpack tests showing reactivity. Human triggering avalanches on this layer remains possible.
Weather Summary
Sunday Night
Mainly cloudy with 0 to 2 cm of snow. 30 to 40 km/h west ridgetop wind. Treeline temperature -12 °C. Freezing levels drop to valley bottom.
Monday
A mix of sun and cloud with 1 to 2 cm of snow. 20 to 30 km/h northwest ridgetop wind. Treeline temperature -13 °C. Freezing levels remain at valley bottom.
Tuesday
Increasing clouds. 20 to 40 km/h northwest ridgetop wind. Treeline temperature -15 °C. Freezing levels remain at valley bottom.
Wednesday
Cloudy with 5 to 15 cm of snow. 50 to 80 km/h southwest ridgetop wind. Treeline temperature rises to -3 °C. Freezing level rises to 1500 m throughout the day.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid freshly wind loaded terrain features.
- 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.
Problems
Persistent Slabs
Recent observations show that a problematic weak layer from early February, of facets overlying a crust, is becoming increasingly triggerable. This layer was the culprit of recent human-triggered avalanches in the region.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Recent snow and strong southwest winds have built fresh wind slabs in lee terrain features. Wind slabs are most reactive where they overlie a crust.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 26th, 2024 4:00PM
