Avalanche Forecast

Issued: Nov 30th, 2023 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

Email

Skies going grey may make early season hazards tougher to manage on Friday. Don't let poor visibility lead you into a steep pocket of wind slab.

Summary

Confidence

Moderate

Avalanche Summary

Last Thursday, a human-triggered size 1 was reported near Invermere at treeline on a west-facing slope. This avalanche failed on the facets at the base of the snowpack.

Observations are limited this time of year. Please consider filling out a MIN report if you do head out in the backcountry! 🙏

Snowpack Summary

Surface conditions are an uninspiring mix of heavily wind-affected surfaces, melt-freeze crust on solar aspects, and 10-15 cm of faceting low density snow in sheltered and shaded areas. Large surface hoar has been spotted growing on most of these surfaces.

A crust with facets or depth hoar exists at or near the ground, which has produced avalanches in the East Purcells and nearby Kananaskis Country. The snowpack is shallower than average for this time of year with depths at treeline ranging from 20 -50 cm, and tapers rapidly below.

Expect early season conditions.

Weather Summary

Thursday Night

Increasing cloud with isolated flurries. Southwest alpine wind 5 to 15 km/h.

Friday

Cloudy with isolated flurries. Minimal accumulations. Southwest alpine wind 5-25 km/h, increasing, strongest in the alpine. Treeline temperature -9.

Saturday

Cloudy with isolated flurries continuing from overnight. Less than 5 cm accumulations. West or southwest alpine wind 15-50 km/h, strongest in the alpine. Treeline temperature -8.

Sunday

Cloudy with flurries bringing up to 5 cm of new snow. Southwest alpine wind 25-60 km/h, increasing, strongest in the alpine.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid areas where the snow feels stiff and/or slabby.
  • Avalanche danger is often elevated in alpine gullies where snow has accumulated.
  • Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.

Problems

Wind Slabs

An icon showing Wind Slabs

The base of our thin snowpack is weak and faceted. Steep pockets of deeper, wind-loaded snow are the most likely to break away from this weak base under the weight of a person or machine.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 1st, 2023 4:00PM