Avalanche Forecast
Issued: Feb 28th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
lbaker,
Avalanche Canada
Very dangerous avalanche conditions continue at higher elevations. Avoid all avalanche terrain.
Natural and human-triggered avalanche activity remains likely.
Summary
Confidence
Moderate
Avalanche Summary
No new avalanches were reported by 4 pm on Wednesday. Poor visibility and high avalanche danger kept many users out of the backcountry.
We expect users who head out on Thursday will see evidence of a widespread natural storm slab avalanche cycle that occurred during the storm.
Several remotely triggered persistent slab avalanches were reported up to size two in the region early this week. This is a clear sign the persistent weak layer is primed for human-triggering.
Snowpack Summary
30 to 70 cm of storm snow overlies wind-affected surfaces and old wind slabs in exposed areas and settling snow in sheltered areas.
Multiple weak layers exist in the upper and mid snowpack. The most concerning weak layer is a widespread crust down 30 to 100 cm with a weak layer of facets or isolated surface hoar above this crust. This problematic layering is very concerning with recent large avalanche activity attributed to it. Although natural avalanche activity may taper out on this layer as the snow stops falling it will remain possible to human-trigger it for some time afterward.
Weather Summary
Wednesday Night
Cloudy with 15 to 20 cm of snow. 20 to 30 km/h southwest ridgetop wind. Treeline temperature rises to -7 °C. Freezing level drops to valley bottom.
Thursday
Partly cloudy with 1 to 5 cm of snow. 10 to 25 km/h southwest ridgetop wind. Treeline temperature -8 °C. Freezing levels around 800 m.
Friday
A mix of sun and cloud with 1 to 3 cm of snow. 10 to 25 km/h south ridgetop wind. Treeline temperature -10 °C. Freezing levels remain at valley bottom.
Saturday
Partly cloudy with 2 to 5 cm of snow. 10 to 20 km/h northeast ridgetop wind. Treeline temperature -12 °C. Freezing levels remain at valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
- Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
- If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.
Problems
Persistent Slabs
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
Storm Slabs
Storm snow and strong winds have built touchy slabs at higher elevations. Deeper deposits are expected in north and east facing terrain around ridgelines. Investigate how the new snow is bonding to the underlying crust as you travel.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 29th, 2024 4:00PM
