Avalanche Forecast

Archived

Feb 10th, 2024–Feb 11th, 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

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

Fresh snow and a supportive crust (in some places) has improved the skiing.

Look for low angle terrain for the best quality turns, and because the buried weak layers are still untrustworthy.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed or reported in the last couple of days. However, our field team reported widespread whumpfing at tree line and alpine areas on Tuesday in the Icefields area. On Monday, the field team triggered a size 1.5 persistent slab on a south aspect at tree line.

Snowpack Summary

10 - 20 cm of recent snow sits over a variable, breakable crust. This crust is 1-3cm thick on shaded aspects, and up to a 15-20cm thick on solar aspects. Big, connected, and sunny tree line features are the most troublesome. Persistent and deep persistent weak layers remain ever-present and active. Do not trust either of these layers.

Weather Summary

Saturday:

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: High -5 °C.

Ridge wind southwest: 10 km/h.

Freezing level: 1600 metres.

The Mountain Weather Forecast is available at Avalanche Canada https://avalanche.ca/weather/forecast

Terrain and Travel Advice

Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

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.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

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.