Avalanche Forecast
Issued: Feb 26th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
kdevine,
Avalanche Canada
Storm slabs may continue to be reactive, especially in wind loaded terrain, and on south facing slopes if solar radiation is strong.
There is the potential to trigger deeper weak layers, resulting in large avalanches. Choose conservative terrain.
Summary
Confidence
Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast. Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
FRIDAY NIGHT - Cloudy with clear periods and a few flurries / light to moderate northwest wind / alpine low temperature near -14Â
SATURDAY - A mix of sun and cloud with isolated flurries / light to moderate northwest wind / alpine high temperature near -13
SUNDAY - Mainly cloudy with a few flurries / strong southwest wind / alpine high temperature near -6 / freezing level 1500 m
MONDAY - Flurries, 5-10 cm / strong southwest wind / alpine high temperature near -6 / freezing level 1500 m
Avalanche Summary
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 Thursday, there were numerous reports of human-triggered size 1-1.5 storm slab, wind slab, and dry loose avalanches. There were also a few reports of natural avalanches up to size 3 in the neighbouring Glacier National Park region.
On Wednesday there were two explosives-triggered size 3 persistent slab avalanches reported on east to southeast aspects around treeline. These were notable as they failed on the late January persistent weak layer.
There was a widespread natural and explosives-triggered avalanche cycle over the weekend and into Monday, with avalanches reported up to size 4. The largest of these avalanches were reported in the Selkirks.
Snowpack Summary
The region has received 60-100 cm of fresh snow in recent days. 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 70-120 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
- Use conservative route selection and resist venturing out into complex terrain.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Be carefull around freshly wind loaded features.
- Even brief periods of direct sun could produce natural avalanches.
Problems
Storm Slabs
Storm slabs may continue to be reactive, especially in wind-loaded areas at higher elevations. Variable winds in recent days may mean that wind loading can be found on all aspects.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
There are several persistent weak layers in the snowpack. The most recent is down 40-80 cm and was formed during the recent cold snap.
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: Feb 27th, 2021 4:00PM
