Avalog
Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Register
Login
Archived

Avalanche Forecast

Nov 28th, 2024–Nov 29th, 2024
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: Bull, Crowsnest North, East Purcell, Elkford East, Elkford West, Purcells, South Rockies.

Weak layers in the snowpack warrant careful terrain choices and watching for signs signs of instability like cracking or whumpfing.

Confidence

Low

Avalanche Summary

A size 1 deep persistent slab, 30–40 cm thick, was human-triggered below treeline on Tuesday. Last weekend, several natural and human-triggered slab avalanches (size 1 to 2) occurred near Invermere, mainly on north aspects. These avalanches failed on weak facets near the base of the snowpack.

Observations from the South Rockies are limited.

Smaller wind slab avalanches could step down to basal facets, triggering larger avalanches.

Snowpack Summary

Up to 15 cm of new snow fell over the weekend. A surface hoar layer, 30 to 40 cm deep, is present on shaded slopes and atop a thin crust on sunny slopes. Near the base of the snowpack, a crust with weak sugary facets above and below caused large avalanches last weekend. Snowpack depths at treeline range from 50 to 70 cm.

Most observations are from the Invermere area, but similar conditions are likely in the South Rockies.

Weather Summary

Thursday Night

Mostly cloudy. 10 to 30 km/h west ridgetop wind. Treeline temperature -12 °C.

Friday

Mostly cloudy with up to 1 cm of snow. 30 to 40 km/h west ridgetop wind. Treeline temperature -10 °C.

Saturday

Mix of sun and cloud. 30 km/h west ridgetop wind. Treeline temperature -8 °C.

Sunday

Mostly cloudy with up to 1 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -8 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid steep terrain, including convex rolls, or areas with a thin, rocky, or variable snowpack.
  • Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
  • Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.

Avalanche Problems

Deep Persistent Slabs

Deep persistent slab avalanches have recently failed on weak faceted snow at the base of the snowpack. This problem is most likely found in the alpine and at treeline on smooth slopes.

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

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 2

Wind Slabs

Recent westerly winds may have formed wind slabs along ridgelines and in exposed terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 1.5