Avalanche Forecast

Issued: Jan 1st, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Keep your guard up! The storm may be tapering, but human triggering remain likely.

Diligently watch for changing conditions throughout the day. Easterly winds may create slabs in atypical locations and at lower elevations than you might usually expect.

Summary

Confidence

Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

Strong low level southeast winds are a precursor to approaching Arctic air. Tuesday we are back in the deep freeze. Pack your puffy jackets and favourite warm beverages it's gonna be frosty!

Saturday Overnight: The storm will begin to taper in the evening, lighter snowfall will continue overnight with up to 10 cm of accumulation. Winds decreasing to moderate to strong from the southwest. Alpine temperatures around -12 C.

Sunday: Continued snowfall, trace to 5 cm of accumulation. Winds shifting southeast in the morning, strong outflow winds expected at all elevations. Temperatures dropping overnight as arctic air repopulates the region. 

Monday: Partially cloudy with light lingering flurries. Moderate to strong southeast winds at all elevations. Temperatures dropping throughout the day, reaching the -20s by the afternoon.

Tuesday: Partially cloudy and cold. Alpine temperatures in the -20s with moderate to strong southeast winds at all elevations.

Avalanche Summary

Operators in the north of the region observed a natural cornice failure, that pulled a slab on the slope below to ground. This area appears to have a shallow snowpack, but shows potential that basal weaknesses in shallow areas may still be triggered with a large load. This highlights how persistent cold temperatures can make cornices facetted and weak. For this reason, it is important to avoid overhead hazard and giving them a wide berth when travelling at ridge crest. Cornice failures can create a large load on the snowpack and trigger deeper weak layers.

If you are out in the mountains, let us know what you see by filling out a Mountain Information Network report! ?

Snowpack Summary

Yesterday's storm totals range from 20-50 cm of new snow. Throughout the storm, strong southwest winds redistributed new snow into wind slabs in the alpine and treeline. Today, strong southeast outflow winds will create fresh, reactive wind slabs in atypical reverse-loading and cross-loading patterns which could catch riders off guard.

In open areas, this new snow is sitting on a heavily wind effected surface, comprised of old harder wind slabs, sastrugi, and areas stripped back to the ground or early season crusts. In sheltered areas, the new snow overlies up to 30 cm of low density, faceted snow from two weeks of prolonged cold temperatures. 

The mid pack is well settled. An early season crust exists near the base of the snowpack. Faceting has been observed around this crust, with no recent avalanche or snowpack test reactivity. Snowpack depth at treeline ranges from 150-230 cm, with highest values in the western part of the forecast region. 

Terrain and Travel

  • Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
  • Be aware of highly variable recent wind loading patterns.
  • Keep your guard up at lower elevations. Wind slab formation has been extensive.

Problems

Wind Slabs

An icon showing Wind Slabs

Yesterday's storm brought 15-40 cm of new snow to the region. Associated strong southwest winds created wind slabs in the alpine and treeline.

A change in the weather pattern today is bringing strong southeast outflow winds which will effect all elevations. Expect fresh, reactive wind slabs to be forming in atypical reverse-loading and cross-loading areas, and down to lower elevations than you might usually expect.

Keep your guard up on all aspects and elevations, and diligently watch for the changing wind direction.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Jan 2nd, 2022 4:00PM