Avalanche Forecast

Issued: Nov 30th, 2022 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Loose Dry.

JA, Avalanche Canada

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

A complex persistent weak layer exists down 30-40cm consisting of surface hoar and or facets, and a solar crust on southerly aspects. If you choose to brave the cold temperatures, pay attention to signs of instability such as cracking and whumpfing, and dig to assess this layer before commiting to avalanche terrain.

Summary

Confidence

Moderate

Avalanche Summary

Field team in the Icefield area on Monday observed shooting cracks and whumpfing on surface hoar layer down 30 cm at tree line and below in sheltered east to northerly aspects. Nov 27th MIN report confirms the presence of the same layer of concern in the Maligne region. Marmot Ski Area reporting no recent results from explosive testing and control.

Snowpack Summary

5cm new snow on Thursday fell on 25-35cm of low density facetted snow. Below this is a layer of concern comprised of surface hoar/facets in sheltered locations treeline and below, and a solar crust on southerly aspects. The surface hoar/facet layer may extend into isolated alpine terrain. Strength of the lower snowpack deteriorating with recent persistent cold temperatures. Height of snow ranges from 60 to 100cm.

Weather Summary

The Arctic ridge of high pressure will reassert itself Thursday with clear, cold, and dry conditions persisting through the weekend. Variable light winds will increase to moderate values from the southwest late Friday.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
Back off if you encounter whumpfing, hollow sounds, or shooting cracks.

Problems

Persistent Slabs

Limited observation in the Alpine. Marmot Basin Ski area reports surface hoar extending into some alpine features. Solar crust on south aspects is also of concern. Dig and assess this layer before commiting to terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Use caution in steep and/or confined terrain features.