Avalanche Forecast

Issued: Feb 12th, 2023 4:00PM

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

Avalanche Canada trettie, Avalanche Canada

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Avoid wind loaded slopes near ridge crests where triggering avalanches is more likely.

Summary

Confidence

Moderate

Avalanche Summary

Over the past couple days there have been several reports of natural, skier and cornice triggered wind slab avalanches, the largest of which were size 3.

On Wednesday, skiers triggered a large, size 2 avalanche near Ningunsaw. The Deep Persistent avalanche was triggered on an east aspect near ridgetop in a thin, rocky start zone and failed on basal facets.

Snowpack Summary

Strong to extreme southwest winds have loaded north and east aspects and pressed or scoured others. Up to 80cm of recent storm snow sits on a crust layer from late January.

Check out this MIN for some great recent observations of the snowpack.

The mid and lower snowpack continues to bond and stabilize. A few concerning weak layers can still be found in the top meter of the snowpack including a surface hoar layer from early January and a crust from late December.

Weather Summary

Sunday Night

Cloudy with up to 5cm of new snow expected. Moderate to strong southwest winds and a low of -3 at 1500m.

Monday

A mix of sun and cloud with the possibility of light flurries bringing a few centimeters of new snow. Moderate northwest winds and temperatures at 1500m falling throughout the day to -9.

Tuesday

Mostly sunny with no new snow expected. Light westerly winds and a high of -8 at 1500m.

Wednesday

Cloudy with flurries bringing up to 5cm of new snow. Moderate southwest winds and a high of -6 at 1500m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Make observations and assess conditions continually as you travel.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Avoid areas with a thin or variable snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs

South through west winds and new snow will add to the wind slab problem and build up cornices.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A number of buried weak layers remain possible to trigger. These layers appear to be most problematic in upper treeline and alpine elevations, in shallow, variable, rocky start zones. A sensitive wind or storm slab overlying this problem could serve as the perfect trigger for a destructive step-down avalanche.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 2.5

Valid until: Feb 13th, 2023 4:00PM