Avalanche Forecast

Issued: Dec 6th, 2021 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Continue to choose terrain that has been sheltered from the wind. The best riding will probably be found by avoiding exposed ridges and steep rolls, where the winds have formed the snow into denser slabs that are more likely to avalanche.

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

Monday Night: Partly cloudy. Possible trace of snow. Moderate west to northwest winds. Alpine high above -15, with a possible temperature inversion.

Tuesday: Overcast. 3-7 cm of snow expected, heavy snow starting overnight and into Wednesday. Strong to Extreme southwest winds, possibly lighter in the south of the region. Alpine temperatures above -10, with a possible temperature inversion.

Wednesday: Mostly cloudy. 10-30 cm snow expected. Strong west to northwest winds. Alpine temperatures around -11.

Thursday: Mostly cloudy. 0-5cm snow expected. Moderate west winds. Alpine temperatures around -13. 

Avalanche Summary

No new avalanches observed.

This Mountain Information Network (MIN) post paints a great picture of conditions in the Cowmoose area on Saturday!

Our North Rockies field team has started their season. They regularly post on the MIN, but you can also give them a follow on Instagram to get lots of great conditions reports and avalanche info:)

Recently, a few large avalanches were observed in the Southeast corner of the region. These avalanches ran on a deep persistent layer, likely one of the crusts from late October or early November.

Snowpack Summary

Saturday night, snowfall was variable across the region. Some areas received up to 15 cm of snow.

Elsewhere, clear, cold nights have promoted surface hoar growth. 5-10 mm surface hoar has been observed in the far south of the region, and is expected to be found in other areas. If you are out in the backcountry, keep an eye out for where it has formed. It may become a new sliding surface as the next storm rolls in on Tuesday night.

Wind slabs will be found in wind exposed terrain in the treeline and alpine. A crust exists below 1700 m. 

The mid snowpack may contain a number of crusts from early to mid November. There is the potential for faceting near these crusts, making them potential sliding layers with the right load or trigger.

The lower snowpack consists of a series of early season crusts. These appear to be strong, but shallow alpine slopes along the eastern side of the Rockies towards Jasper may have weaker, faceted snow near the ground. Avoid thick to thin areas where you are more likely to be able to trigger this deeper instability. 

Snowpack depths are anticipated to be approaching 3 m in the alpine and around 150 cm at treeline. 

Terrain and Travel

  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
  • Wind slabs may be poorly bonded to the underlying crust.

Problems

Wind Slabs

An icon showing Wind Slabs

The recent forecaster blog does a great job of capturing the challenging travel and decision-making we'll likely encounter in the backcountry right now. 

Wind slabs are likely to be found near ridgelines and exposed terrain in the treeline and alpine.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Dec 7th, 2021 4:00PM

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