Avalanche Forecast
Issued: Feb 28th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
kdevine,
Avalanche Canada
Wind slabs are likely to be encountered and may be reactive to human triggering. Watch for signs of instability such as whumpfing, cracking, and recent avalanches.
There is still the potential to trigger persistent weak layers. Choose conservative terrain.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
SUNDAY NIGHT - Mainly cloudy with a few flurries, 5 cm / moderate to strong southwest wind / alpine low temperature near -8 / freezing level 1400 m
MONDAY - Mainly cloudy with a few flurries, 5 cm / moderate to strong southwest wind / alpine high temperature near -5 / freezing level 1500 m
TUESDAY - Mainly cloudy with isolated flurries / moderate southwest wind / alpine high temperature near -7 / freezing level 1200 m
WEDNESDAY - A mix of sun and cloud / moderate south wind / alpine high temperature near -5 / freezing level 1400 m
Avalanche Summary
There was a widespread avalanche cycle during the storm last weekend and into last Monday with avalanches reported up to size 4.Â
Since the storm eased off early last week, there have been daily reports of natural and explosives-triggered avalanches between size 1-3, and human-triggered avalanches between size 1-2. The size and frequency of these avalanches have decreased slightly each day since the storm ended.
The following are reports of a few notable avalanches from the past week.
On Friday there was a report of a human-triggered size 2 avalanche that resulted in a full burial in a cutblock near Blue River. Check out the MIN report here.
On Wednesday there were two explosives-triggered size 3 persistent slab avalanches reported on east to southeast aspects around treeline, east of Revelstoke near Albert Canyon. These were notable as they failed on the late January persistent weak layer.
Snowpack Summary
The region has received 60-100 cm in the past week. Deep wind deposits may be found in lee terrain features in the alpine and open treeline areas, and will likely remain reactive to human triggers. All of this new snow sits over weak, faceted snow from the recent cold snap.Â
There is now 80-120 cm of snow above the late January persistent weak layer which is composed of surface hoar in sheltered areas in the trees and/ or a crust on steep solar aspects.Â
Terrain and Travel
- Be aware of highly variable recent wind loading patterns.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
Recent (and ongoing) southwest winds are likely forming wind slabs at upper elevations. Previous variable winds may mean that wind slabs could be found on all aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
60-100 cm of snow sits on a persistent weak layer of facets that was buried in mid-February.
The late January persistent weak layer is down 70-120 cm. Though avalanches on this layer have been sporadic, they have been large.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 1st, 2021 4:00PM
