Avalanche Forecast

Archived

Feb 3rd, 2025–Feb 4th, 2025

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.

Below Treeline

Natural avalanches unlikely.

Regions

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

10-15 cm of fresh snow from the weekend has improved skiing, but wind slabs remain a concern, especially in wind-exposed terrain.

Frigid temperatures persist this week—be prepared if you are heading out.

Confidence

High

Avalanche Summary

Last weekend's patrol up Maligne and the Icefield noted very little new activity. One loose dry size 1.5 observed on Saskatchewan North avalanche path. On Thursday, Marmot Basin triggered a size 2 avalanche failing on the deep basal 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

10-15cm of fresh soft snow sits 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

Tuesday

A mix of sun and cloud with isolated flurries. Alpine temperature: High -22 °C. Ridge wind east: 10 km/h.

Wednesday

A mix of sun and cloud. Alpine temperature: Low -19 °C, High -15 °C. Ridge wind northwest: 10-20 km/h.

Thursday

A mix of sun and cloud. Alpine temperature: Low -20 °C, High -14 °C. Light ridge wind.

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.