Avalanche Forecast

Archived

Feb 16th, 2023–Feb 17th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Cariboos, Blue River, Clearwater, McBride, Premier, Quesnel, Sugarbowl, Clemina, North Monashee, Renshaw, Robson.

Cornices continue to grow with new snow and wind, this new growth is overhanging and may break off naturally. Avoid exposure to steep open slopes where there is exposure to cornices.

Confidence

Moderate

Avalanche Summary

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 coupled with moderate west winds will be developing new wind slabs at treeline and alpine elevations. A thin surface crust can be found on steep solar aspects. 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

Thursday night

Mainly cloudy, snowfall easing accumulation 3 to 5 cm, 20 to 30 km/h westerly winds, treeline temperatures -10 °C.

Friday

Mostly clear increasing clouds overnight, isolated flurries, increasingly snowy overnight into Saturday morning 4 to 6 cm accumulation, 20 to 30 km/h west winds, treeline temperatures -10 °C.

Saturday

Cloudy with snowfall easing in the afternoon, 4 to 6 cm accumulation, 15 to 20 km/h west winds, treeline temperatures -8 °C.

Sunday

Cloudy with snowfall, 5 to 10 cm accumulation, 20 to 30 km/h west winds, treeline temperatures -7 °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

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.