Avalanche Forecast

Archived

Jan 31st, 2025–Feb 1st, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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.

Alpine

Natural avalanches possible, human triggered probable.

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.

Weather forecasts show uncertainty in amount of snow that will fall in the next 24 hours.

Combined with loading winds, new snow may form windslabs with the potential to overload the weak layers at the base of the snowpack.

Confidence

Moderate

Avalanche Summary

Yesterday the local ski hill triggered a size 2 avalanche failing on the basal deep persistent layer using explosives.

Several natural wind slab avalanches to size 2 as well as smaller loose dry avalanches were observed in the Icefields area on January 29th.

Snowpack Summary

Incoming snow is falling on a variety of surfaces depending on location, including melt freeze crusts, sun crusts, hard wind slabs, and soft faceted snow. These overlie a generally weak and faceted mid-pack. At the bottom of the snowpack are the early season crusts, which are faceting and surrounded by large depth hoar. The snowpack is 70-130 cm in depth at tree line, and thins quickly below.

Weather Summary

Saturday

Cloudy with sunny periods. Precipitation: Up to 10mm. Alpine temperature: High -8 °C. Ridge wind southwest: 15 km/h gusting to 45 km/h. Freezing level at valley bottom.

Sunday

A mix of sun and cloud with isolated flurries. Precipitation: Trace. Alpine temperature: Low -30 °C, High -17 °C. Ridge wind light to 15 km/h. Freezing level at valley bottom.

Monday

Sunny with cloudy periods. Precipitation: Nil. Alpine temperature: Low -28 °C, High -20 °C. Ridge wind east: 10 km/h. Freezing level at valley bottom.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

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.