Avalanche Forecast

Archived

Jan 13th, 2025–Jan 14th, 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 possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Regions

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

Latest northwesterly winds deposited wind slabs in unusual places, causing reverse loading in the alpine. Identify wind-impacted snow by watching for sudden changes in surface texture and hardness.

Confidence

Moderate

Avalanche Summary

A couple low elevation size 1.5 loose dry avalanches were noted Saturday at highway level Coleman cliffs. Marmot basin explosive triggered a size 2 to ground on a North aspect at tree line on Friday. The slope was not previously controlled.

Snowpack Summary

5cm new snow at the icefields Friday night. The snowpack is 60-120cm in depth at tree line. 10-30cm sits atop a weakening melt freeze crust and surface hoar layer from early December. The middle of the snowpack is facetted and there is a deep persistent layer at the base of the snowpack consisting of a decomposing melt freeze crust and depth hoar.

Weather Summary

Expect sun, cloud, no new snow, ridgetop winds of 30- 40 km/h at ridge tops, and -5 °C in the alpine on Tuesday. Wednesday and Thursday will see strong westerly winds shifting to southwesterly and precipitation beginning on Wednesday and most amounts expected to arrive on Thursday, accumulating to up to 15 cms by Friday morning.

Terrain and Travel Advice

Approach lee and cross-loaded slopes with caution.
Be careful with wind-loaded pockets, especially near ridge crests and rollovers.

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.