Avalanche Forecast
Issued: Feb 23rd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
rgoddard,
Avalanche Canada
Atypical winds may have produced reactive wind slabs in atypical locations.
Use caution as you transition into wind-affected terrain.
Summary
Confidence
Moderate
Avalanche Summary
Wednesday's avalanches were produced primarily from wind slabs that were created from the recent northeast wind. These wind slab avalanches were triggered naturally and with the use of explosives and some of them were very large, up to size 3.
Observations on Tuesday reported natural avalanche activity that produced avalanches that ranged in size between 1.5 and 4. Our field team reported witnessing several wind slab avalanches up to size 2.5 in extremely steep terrain. Local operators reported wind slab, storm slab, and also persistent and deep persistent slab avalanches. The persistent and deep persistent layers have been relatively quiet since February 16th. This is a good reminder that they could still be reactive in the right location.
On Sunday, a notable skier accidental size 2 storm slab occurred in the backcountry near Terrace. See details in the MIN report.
Snowpack Summary
Variable winds, predominantly and most recently from the northeast, have redistributed up to 40 cm of recent snow at all elevations in exposed areas.
Up to 80 cm now sits over a layer of small surface hoar, facets, and wind-affected surfaces.
A crust from late January exists around 140 to 180 cm below the surface. Beneath the crust, the snowpack is generally consolidated but as you move further inland there are instabilities found near the ground where the snowpack is thinner.
The total height of snow varies between 450 cm near the coast and 250 cm further inland.
Weather Summary
Thursday Night
Clear with clouds increasing in the morning, no accumulation, winds northeast 25 km/h gusting to 40, treeline temperatures -18 °C.
Friday
Mostly cloudy, trace accumulation starting late in the day, winds northwest 20 to 35 km/h, treeline temperatures -18 °C.
Saturday
Cloudy, 10 to 20 cm accumulation with greatest amounts towards coastal regions, winds southwest 30 km/h gusting to 50, treeline temperatures around -15 to -10 ºC.
Sunday
Cloudy with possible late-day sunny periods, up to 5 cm accumulation in some areas, winds, west southwest 20 to 30 km/h, treeline temperatures -12 ºC and rising throughout the day.
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.
- Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Avoid exposure to slopes that have cornices overhead.
Problems
Wind Slabs
The most recent wind has been coming from the north and northeast but earlier this week they were coming from the southwest and west earlier this week. For this reason, you may encounter wind slabs on all aspects at higher elevations. You should suspect all wind slabs to be reactive and for avalanches to be triggered by riders.
If an avalanche is triggered it may create enough load to trigger weak layers buried further down in the snowpack. Where this would be most prevalent is the northern part of our region. Keep this in mind when traveling in the backcountry and mitigate this problem by choosing low-consequence terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 24th, 2023 4:00PM
