Avalanche Forecast

Archived

Nov 29th, 2024–Dec 2nd, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

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.

Recent winds have created new wind slabs and have stripped some areas of snow. More slabs will likely be formed with continued winds and snowfall this weekend.

There is still good riding to be had in sheltered areas.

Confidence

Moderate

Avalanche Summary

There have been several explosive controlled and natural avalanches up to size to 2 observed in the past week to the south of Jasper National Park, failing on the October crust at the base of the snowpack.

Snowpack Summary

15 cm of low density snow in sheltered areas overlies a faceted midpack. The November 20th surface hoar layer was found down 60 cm in one pit in the alpine. At treeline there is a crust down 30 cm. The October crust is widespread and is found near the base of the snow pack and has facets above and below. Snow depth is roughly 70 cm at treeline and tapers rapidly below.

Weather Summary

Friday Night

Mainly cloudy with isolated flurries.

Precipitation: Trace

Alpine temperature: Low -12 °C.

Ridge wind southwest: 15-30 km/h

Saturday

Cloudy with scattered flurries.

Accumulation: 5 cm.

Alpine temperature: High -7 °C.

Ridge wind southwest: 20-40 km/h

Sunday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -8 °C, High -7 °C.

Ridge wind west: 10 km/h.

Terrain and Travel Advice

Be careful as you transition into wind-affected terrain.
Seek out sheltered terrain where new snow hasn't been affected by wind.

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.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.