Avalanche Forecast

Issued: Feb 18th, 2023 4:00PM

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

Avalanche Canada trettie, Avalanche Canada

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Carefully assess for wind slab as you move through terrain. Be especially cautious in shallow snowpack areas where triggering a deep persistent slab remains possible.

Summary

Confidence

Moderate

Avalanche Summary

No significant avalanches were reported in the region on Friday but observations were limited.

One natural size two deep persistent slab was reported on Thursday in the northern part of the region. It was on a northeast aspect in the alpine. Deep persistent slab avalanches like this one continue to be reported atleast once a week in shallow snowpack areas.

Snowpack Summary

Up to 70cm of snow has fallen with moderate to strong southerly and westerly winds. This most recent snow has buried a variety of surfaces including small surface hoar and old wind effected surfaces. windward slopes are generally scoured or pressed with wind slab found on north and east aspects.

Several layers of facets, crusts or surface hoar can be found in the top 1.5 meters of the snowpack.

In shallow snowpack areas layers of facets from November and December are near the bottom of the snowpack and have likely been responsible for some large avalanches.

Weather Summary

Saturday Night

Cloudy with up to 10cm of new snow expected. Moderate to strong westerly winds and a low of -3 at 1500m.

Sunday

Cloudy with up to 5cm of new snow expected. Moderate to strong northwest winds and temperatures at 1500m around -3.

Monday

Cloudy with up to 10cm of new snow. Light variable wind and a high of -5 at 1500m.

Tuesday

Mostly sunny with the possibility of light flurries bringing trace amounts of new snow. Light northeast winds and temperatures at 1500m falling to -15.

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.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • 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

AS the winds shift to a more westerly direction wind slabs could be found on all aspect.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Over the past few weeks we have recieved reports of large deep persistent slab avalanches. Triggering an avalanche on deeply buried facets is unlikely but very consequential. Avoid shallow, steep and rocky start zones at treeline and above where triggering a deep persistent slab could be possible.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Feb 19th, 2023 4:00PM

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