Avalanche Forecast

Archived

Jan 26th, 2023–Jan 27th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

Dynamic changes in temperature, reverse loading with moderate north winds, and 10-15cm of new snow is forecast by the end of the day Friday.

Avoid exposing yourself to avalanche terrain, and allow the snowpack to adjust.

Confidence

Moderate

Avalanche Summary

Snowballing and previous loose wet activity was noted on steep west aspects near Weeping Wall.

A large avalanche (sz3) observed Thursday in the Icefields. Started in the alpine, running mid-track on deep facets, well into below treeline.

If you're out in the hills, don't forget to post to the MIN. Every bit of information helps.

Snowpack Summary

5-10cm from this past week with a further 5-10cm expected overnight Thursday. The wind is loading new snow in a reverse pattern, building new windslab on all aspects in the alpine. The weak upper snowpack is comprised of 20-30cm of facets. with larger facets and cupped depth hoar to ground. This deep persistent weakness may be near the surface in shallow snowpack areas. HS depths vary from 40-110cm.

Weather Summary

Dramatic temperature change begins overnight Thursday and progressively cools through the day Friday. Low of -27 by Saturday morning. Up to 12cm HST with moderate north winds.

Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast

Terrain and Travel Advice

In times of uncertainty conservative terrain choices are our best defense.
Avoid areas with overhead hazard.

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.