Avalanche Forecast
Issued: Mar 8th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
lbaker,
Avalanche Canada
Avoid shallow rocky terrain where the snowpack transitions from thick to thin and triggering the deep persistent layer is more likely.
Summary
Confidence
Moderate
Avalanche Summary
On Monday, a few natural, size three avalanches were observed in the region. A cornice triggered a wind slab avalanche on a steep rocky north-facing slope in the Selkirks. In the Rockies, a deep persistent slab avalanche was triggered by a cornice or solar input in extreme, rocky terrain. See the MIN for a photo.
Snowpack Summary
40-50 cm of storm snow from earlier in the week sits over wind affected surfaces in sheltered locations. Wind slabs may be found on all aspects due to variable winds in the past few days. A melt-freeze crust covers the surface of steep solar slopes.
The mid-snowpack is generally well settled. The lower snowpack is made up of a widespread layer of large, weak basal facets and depth hoar in some areas. this weakness has been responsible for a number of recent very large, destructive avalanches and will continue to be a concern.
Weather Summary
Wednesday Night
Partly cloudy. Easterly ridgetop winds 15-25 km/h. Treeline temperatures, low of -15.
Thursday
A mix of sun and cloud with isolated flurries, trace accumulation. Southerly winds 15-25 km/h. Treeline temperatures, high of -10.
Friday
Cloudy with scattered flurries, 3-6 cm accumulation. Easterly ridgetop winds 15-25 km/h. Treeline temperatures, high of -10.
Overnight flurries continue 2-3 cm accumulation. Winds switch to the southwest 20 km/h.
Saturday
Partly cloudy with isolated flurries, trace accumulation. Southwest ridgetop winds 20 km/h. Treeline temperatures, high of -10.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid areas with a thin or variable snowpack.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
Problems
Deep Persistent Slabs
The base of the snowpack remains very weak. Very large human triggered avalanches are possible at treeline and above. Avoid shallow and rocky areas, where the snowpack depth is highly variable. This is a very concerning avalanche problem and should stay in your mind when traveling in the backcountry.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Shifting winds have created wind slabs in lees of exposed features in the alpine and isolated features at treeline. Continually assess wind affect as you move through the terrain.
Be aware that if triggered wind slab avalanches could step down to deeper layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 9th, 2023 4:00PM
