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
Weather Forecast
FRIDAY NIGHT - Cloudy with clear periods and a few flurries / light to moderate northwest wind / alpine low temperature near -13
SATURDAY - A mix of sun and cloud with isolated flurries / moderate northwest wind / alpine high temperature near -13
SUNDAY - Mainly cloudy with a few flurries, 5 cm / strong southwest wind / alpine high temperature near -7 / freezing level 1500 m
MONDAY - Mainly cloudy with a few flurries, 5 cm / strong southwest wind / alpine high temperature near -6 / freezing level 1500 m
Avalanche Summary
On Thursday, there were numerous reports of size 1-2 natural, human and explosives-triggered storm slab avalanches. Many of these were triggered remotely (from a distance).
On Wednesday, there were a few reports of size 1.5-2 natural and human-triggered storm slab avalanches in the alpine and at treeline, on all aspects.
On Tuesday, there were several reports of natural, human and explosives-triggered avalanches up to size 3, though most were in the size 1-2 range.
During the storm last weekend and into Monday, there was a widespread natural and explosives-triggered avalanche cycle, with avalanches ranging from size 2-4. The largest avalanches were reported in the Selkirks in the northern portion of the region.
There have been a few reports from the south of the region of sporadic persistent slab avalanches failing on the late January persistent weak layer. These have been around size 2, human-triggered, and out of steep, cliffy, unsupported terrain around treeline.
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.
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. Very isolated activity on this layer has been observed recently.
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
40-80 cm of recent snow sits on a persistent weak layer of facets.
Another persistent weak layer buried 80-120 cm deep is composed mainly of surface hoar. We are still seeing isolated activity on this layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 27th, 2021 4:00PM
