Avalanche Forecast

Archived

Dec 19th, 2024–Dec 20th, 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 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.

Keep your overhead hazard to a minimum. Large avalanches running to ground in the alpine have been observed in Jasper as a result of the new snow and winds.

Confidence

Moderate

Avalanche Summary

Several avalanches were observed along the Churchill Range on east faces in alpine up to size 2.5 and running to ground. Some of these avalanches were caused by falling cornices.

Snowpack Summary

15-20 cm of snow fell on Wednesday at the Parker Ridge Area. The 7mm Surface Hoar that formed last week is likely flattened by winds but assume it could be preserved under new snow in sheltered locations. The mid and lower snow pack has multiple layers of surface hoar in sheltered terrain, melt freeze crusts and facets.

Weather Summary

Friday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: High -4 °C.

Ridge wind southwest: 15-35 km/h.

Freezing level: 1600 metres.

Saturday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -4 °C, High -3 °C.

Ridge wind southwest: 10-30 km/h.

Freezing level: 1800 metres.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
Be careful as you transition into wind-affected terrain.
Small avalanches may cause climbers to fall or bury belayers and gear.

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.