Avalanche Forecast

Issued: Nov 28th, 2020 4:00PM

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

Avalanche Canada ghelgeson, Avalanche Canada

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Last week's snow has been formed into wind slabs at upper elevations which may be sensitive to human triggering. Watch for wind slabs in the alpine and "alpine like" features at treeline. 

Summary

Confidence

Low - Forecast snowfall amounts are uncertain.

Weather Forecast

The weather forecast is rather unexciting for the South Rockies over the next few days.

SATURDAY NIGHT: Freezing level at valley bottom, light to moderate southwest wind, trace of snow possible. 

SUNDAY: Scattered cloud cover, moderate southwest wind, freezing level rising to between 1000 and 1600 m in the afternoon, no precipitation expected. 

MONDAY: Clear skies at dawn with increasing cloud cover building in after lunch, moderate to strong southwest wind, freezing level rising to about 1100 m, no significant precipitation expected. 

TUESDAY: Scattered cloud cover, freezing level around valley bottom, light to moderate northwest wind, no precipitation expected.

Avalanche Summary

There have been a few reports of small (size 1) naturally triggered wind slab and loose dry avalanches in steep rocky terrain over the past few days. A few of them released near the ground, but were only 20-50 cm thick. Ongoing wind transport is likely forming more wind slabs over the weekend, so be alert to slopes that have been wind affected.

Please submit your observations to the Mountain Information Network! 

Snowpack Summary

Strong wind over the weekend will continue to redistribute the 10-15 cm of snow that fell on Tuesday night. Snowpack depths are variable with reports of 50 to 100 cm in terrain that hasn't been scoured by the wind. There are some reports of a hard crust buried about 30 cm below the surface, which could be a bed surface for wind slab avalanches. There is most likely a crust at the bottom of the snowpack, and there have been a few reports suggesting weak snow may be forming around these crusts. This layer could become a bigger concern when it gets buried deeper.

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.

Problems

Wind Slabs

An icon showing Wind Slabs

Watch for freshly formed wind slabs in the alpine, and "alpine like" features at treeline. These slabs may be poorly bonded to the underlying snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 29th, 2020 4:00PM

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