Avalanche Forecast

Archived

Dec 23rd, 2024–Dec 24th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

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.

High elevation winds are increasing in speed and power the next couple of days with 80km/hr at Icefields and 100km/hr at Maligne. Expect windslabs to develop rapidly. Caution is advised for the next couple of days until the wind's impacts can be ascertained.

Confidence

Low

Avalanche Summary

No patrol occurred Monday and nothing new reported. Over the weekend the ski hill using explosives triggered two size 1.5 deep persistent avalanches and a small windslab.

Snowpack Summary

A dusting of new snow sits on the 15cm that fell last week and was redistributed by southwest winds. This wind has loaded lee features, creating windslabs and stripped exposed areas. In sheltered areas this snow sits on a weak layer of 7mm Surface Hoar. The mid and lower snow pack has multiple layers of surface hoar in sheltered terrain, melt freeze crusts and facets. Two of these are the deep persistent slab interfaces near the ground.

Weather Summary

Tuesday will deliver flurries, 6 cm of snow, -5 °C, SW winds 25 gusting to 80 km/h. Wednesday will be similar with 5cm of snow and gusting SW 55km/hr winds. Expect Thursday to be sun, flurries, and light SW winds.

Terrain and Travel Advice

Be careful 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.

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.