Avalanche Forecast
Issued: Feb 22nd, 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.
rgoddard,
Avalanche Canada
Northeast winds will have produced wind slabs.
Triggering a deep persistent slab remains possible, especially in areas with a thin snowpack.
Sheltered and low-consequence terrain will offer the safest riding.
Summary
Confidence
Moderate
Avalanche Summary
No significant avalanches were reported in the past few days.
On Thursday, there was a report of a natural deep persistent slab avalanche, size two, from the northern part of the region. It was on a northeast aspect in the alpine. Deep persistent slab avalanches like this one continue to be reported at least once a week in shallow snowpack areas. something to keep in mind when traveling through the backcountry.
Snowpack Summary
Monday saw 30 to 40 cm of new snow. This has likely been redistributed by northeast winds in exposed areas at most elevations.
Several layers of facets, crusts/surface hoar can be found in the top 1.5 meters of the snowpack. For the most part, the mid-pack is generally strong.
Weak layers of note from November and December are near the bottom of the snowpack, 150 to 200 cm from the surface.
The total height of snow at treeline is between 200 and 280 cm.
Weather Summary
Wednesday Night
Clear, no accumulation, winds northeast 35 km/h gusting to 60, treeline temperatures -20 to -25 °C.
Thursday
Sunny, no accumulation, winds northeast 40 km/h, treeline temperatures -20 to -25 °C.
Friday
Mostly cloudy, trace accumulation, winds west 20 to 40 km/h, treeline temperatures around -20 °C.
Saturday
Cloudy, 5 to 15 cm accumulation starting Friday evening, winds southwest 20 km/h gusting to 45, treeline temperatures -18 ºC.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Keep your guard up at lower elevations. Wind slab formation has been extensive.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Avoid areas with a thin or variable snowpack.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
Problems
Wind Slabs
Northeasterly winds will redistribute 20 to 40 cm of recent new snow into fresh, reactive wind slabs. These slabs will form in a reverse loading pattern and could be found at elevations lower than expected. Wind slabs may be particularly reactive where they overlie a crust.
Aspects: North, South East, South, South West, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Over the past few weeks, we have received reports of large deep persistent slab avalanches. These reports have been mostly from the northern part of our region. Although triggering an avalanche on these deeply buried layers is unlikely, the result would be a large destructive avalanche. Avoid shallow, steep, and rocky start zones at treeline and above where triggering a deep persistent slab could be possible.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 23rd, 2023 4:00PM
