Avalanche Forecast

Archived

Dec 14th, 2024–Dec 15th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Purcells, East Purcell.

Avoiding large features and enjoying low-angle riding is a good way to manage a deep persistent problem.

Tune into conditions that change with aspect and elevation.

Confidence

Moderate

Avalanche Summary

No recent avalanche activity has been reported since Tuesday when a few natural wind slabs were observed in north-facing alpine terrain.

Observations are limited, please submit a MIN if you head into the backcountry!

Snowpack Summary

10 to 15 cm of wind-affected snow sits on sun crusts on south-facing slopes, surface hoar in sheltered areas, and previously wind-affected snow.

In the Invermere area, avalanches have been failing on weak faceted snow at the base of the snowpack. So far reports suggest this does not extend throughout the forecast region, but is likely found in shallow snowpack areas.

Treeline snow depths are generally 50 to 70 cm, with deeper wind-loaded pockets in the alpine.

Weather Summary

Saturday Night

Partly cloudy with 1 to 2 cm of snow. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -9 °C.

Sunday

A mix of sun and cloud with up to 2 cm of snow. 15 to 30 km/h west ridgetop wind. Treeline temperature -9 °C.

Monday

A mix of sun and cloud, increasing, with 1 cm of snow in the afternoon. 10 to 20 km/h south ridgetop wind. Treeline temperature -11 °C.

Tuesday

A mix of sun and cloud. 15 km/h west ridgetop wind. Treeline temperature -8 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be alert to conditions that change with aspect and elevation.
Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and slopes above cliffs.

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.