Avalanche Forecast
Issued: Feb 15th, 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.
llarson,
Avalanche Canada
Watch out for areas where avalanches are more likely, like exposed terrain where the wind is consolidating the new snow into a slab. Back off into simple terrain as snowfall amounts increase and the snow starts to consolidate.
Summary
Confidence
Avalanche Summary
Several natural very large avalanches were reported in neighboring regions to the south that failed down to the deep persistent weak layer found near the base of the snowpack.
Reports of natural and cornice-triggered wind slabs continue to trickle in reminding us that human triggering of these layers remains possible.
Going forward new snow and continued winds will build new wind slabs over old wind slabs that remain reactive to large loads.
Snowpack Summary
Roughly 15 to 20 cm of new snow will accumulate throughout the day. This new snow is coupled with moderate to strong southwest winds that will be developing touchy new wind slabs at treeline and alpine elevations. Below this, the upper snowpack continues to settle and bond to previous surfaces.
The mid-pack is showing signs of strengthening. A surface hoar layer down roughly 60 to 80 cm has not produced avalanches recently but can still be found in isolated terrain features specifically sheltered, treeline, and upper below treeline.
The lower snowpack is composed of large and weak facets from November located near the base of the snowpack. Additional load or step-down avalanches over the next few days may wake this layer up.
Weather Summary
Wednesday night
Clouds increase overnight with snowfall, accumulation of 2 to 5 cm, 10 to 20 km/h southwest winds, and treeline temperatures -9 °C.
Thursday
Mainly cloudy, 10 to 15 cm new snow, 30 to 40 km/h south winds, treeline temperatures -10 °C.
Friday
Cloudy with flurries increasing overnight, 20 to 30 km/h southwest winds, treeline temperatures -10 °C
Saturday
Cloudy with snowfall, 5 to 10 cm accumulation, 20 to 30 km/h southwest winds, treeline temperatures -8 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Wind Slabs
Expect wind slabs to be reactive on Thursday, as new snow accumulates. Recent strong southwest wind formed wind slabs in lee terrain features. Around 10 to 20 cm of new snow on Thursday will rest atop these slabs.
Aspects: North, North East, East, South East, North West.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer is most prominent in upper treeline and alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain. Your best defence is to stay diligent in choosing low-consequence terrain away from overhead exposure.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 16th, 2023 4:00PM
