Avalanche Forecast

Archived

Dec 17th, 2024–Dec 18th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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 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.

Watchout if you find locally higher precipitation amounts. This could mean that the avalanche danger is higher than what is on the forecast.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed in the Jasper Region but a close call occurred in the Bow Summit zone in a similar snowpack. See the MIN for more information.

Snowpack Summary

The 7mm Surface Hoar that formed last week is likely flattened by winds but assume it could be preserved under a few centimeters of new snow in sheltered locations. An older buried surface hoar layer is found in sheltered alpine areas 40cm down. Lower down in the snowpack there are crusts with large faceted crystals above and below.

Weather Summary

Wednesday

Flurries.

Accumulation: 9 cm.

Alpine temperature: High -4 °C.

Ridge wind west: 20 km/h gusting to 70 km/h.

Freezing level: 1500 metres.

Thursday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -10 °C, High -7 °C.

Ridge wind southwest: 15-30 km/h.

Freezing level at valley bottom.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
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.