Avalanche Forecast

Archived

Feb 7th, 2023–Feb 8th, 2023

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 possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Jasper, Brazeau, Churchill, Fryatt, Maligne, Marmot, Miette Lake, Pyramid.

North and eastern parts of the Jasper bulletin region seeing significantly less precipitation than the Icefields area. 10cm new snow is possible by Wednesday morning. Watch for additional wind slab development with continued moderate to strong southwest winds.

Confidence

Moderate

Avalanche Summary

No patrol on the Maligne road. Shangrila MIN for more details on avalanche conditions in the area.

Don't forget to post avalanche observations to the MIN.

Snowpack Summary

Trace to 2cm of precipitation in the last 24 hours. Moderate to strong southwest wind continues to strip snow in exposed alpine features creating wind slab in the alpine and into exposed tree line. A weak melt freeze crust facet combo down 25cm below 2100m is showing sudden collapse results in snow pit tests. Generally, the bottom of the snowpack is weak facets and depth hoar. The snowpack ranges from 50 to 120cm.

Weather Summary

The tail end of a low pressure system is expected overnight Tuesday and may bring up to 10cm of new snow in the north and eastern parts of the bulletin region. Winds will be moderate to strong from the southwest and west - freezing level will remain at or near valley bottom. Clearing trend is expected on Wednesday with continued moderate to strong westerly winds.

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

Terrain and Travel Advice

In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Watch for signs of slab formation throughout the day.

Problems

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.

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.