Avalanche Forecast

Archived

Jan 20th, 2025–Jan 21st, 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, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Wind slabs remain the primary concern. Cold temperatures will linger through the week.

Most alpine and treeline areas have been affected by wind.

Confidence

Moderate

Avalanche Summary

Avalanche control near Parkers on Friday (Jan 17) produced slab avalanches up to size 2.5. These avalanches stepped down to the Deep Persistent layer making them larger than expected.

Snowpack Summary

Widespread wind affect in the TL and Alpine regions. Cold temps, promoting facetting continue to undermine the overall strength of the snowpack. A deep persistent layer at the base of the snowpack remains problematic without a solid mid-pack bridging a decomposing crust and depth hoar. The snowpack is 70-130 cm in depth at treeline. Valley bottom travel is difficult in the weak, loose facets.

Weather Summary

Overnight

Clear with cloudy periods. No Precip. Alpine temperature: Low -14 °C. Ridge wind light to 20 km/h.

Tuesday

A mix of sun and cloud. Alpine temperature: Low -16 °C, High -13 °C. Ridge wind west: 15 km/h gusting to 45 km/h.

Wednesday

Cloudy with sunny periods and isolated flurries. Alpine temperature: Low -12 °C, High -9 °C. Ridge wind west: 10-20 km/h.

Terrain and Travel Advice

Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
Avoid exposure to overhead avalanche terrain; avalanches may run surprisingly far.

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.