Avalanche Forecast

Issued: Jan 11th, 2023 4:00PM

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

Avalanche Canada jleblanc, Avalanche Canada

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Dangerous avalanche conditions will develop with the upcoming storm.

Choose low-angle, well-supported terrain with no overhead hazard.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were reported in the region since Wednesday. Small sluffing was observed on steep north slopes. Please continue to post your observations and photos to the Mountain Information Network. It helps strengthen our data gathering.

Snowpack Summary

Previous strong southerly winds have scoured alpine south-facing terrain and affected the recent snow (10-15 cm) on open alpine features. Sun-affected snow was also observed on steep south slopes.

In sheltered terrain, 40 to 60 cm of low-density snow sits over a crust formed in late December. This crust varies in thickness throughout the terrain and elevation. Uncertainty remains about the robustness of this crust above 2100 m. Small avalanches could potentially run down on this layer, creating larger-than-expected avalanches.

There is a widespread layer of facets and depth hoar at the bottom of the snowpack, which remains a concern for triggering with large loads or on thin spots. Snowpack depths around treeline are about 150 cm deep. The snowpack below treeline is very shallow and faceted.

Weather Summary

A strong storm will affect the region early Thursday. Moderate to heavy snowfalls are expected before the subtropical flow pushes warm air and rain onto the region until Saturday.

Wednesday night

Increasing cloudiness, no precipitation, light southeasterly winds increasing to moderate, freezing levels around 1200 m, low of -3C at treeline.

Thursday

Stormy 15-30 cm, rain at lower elevations, moderate southerly winds gusting to 50 km/h at ridge tops, freezing levels around 1500 m rising to 1800 m, high of 0C at treeline. 15-20 cm wet snow/ rain overnight.

Friday

Rain 10-15 mm, snow at higher elevations only, moderate southerly winds gusting to 50 km/h at ridge tops, freezing levels rising to 2000 m, high of +2C at treeline.

Saturday

Cloudy, lingering flurries, moderate southwesterly winds gusting 40 km/h, freezing levels dropping to 1500 m, high of -3C at treeline.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for changing conditions today, storm slabs may become increasingly reactive.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Closely monitor how the new snow is bonding to the crust.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

Problems

Storm Slabs

An icon showing Storm Slabs

At upper elevations, forecasted snow amounts will likely develop reactive storm slabs. Human-triggered avalanches will be likely, especially on leeward terrain features where deposits are deep. Closely monitor the bonding of the new snow with the underlying surface. Be aware that slab avalanches could step down to a crust layer and produce larger-than-expected avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 12th, 2023 4:00PM