Avalanche Forecast

Issued: Mar 5th, 2023 4:00PM

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

Avalanche Canada TT, Avalanche Canada

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Careful snowpack evaluation, cautious route-finding and conservative decision-making are essential while waiting out the deep persistent instabilities.Thin to thick areas are the most likely skier trigger points.

Summary

Confidence

Moderate

Avalanche Summary

A number of large avalanches up to size 3 were observed last week. Natural activity has tapered off since but the snowpack is very sensitive to small inputs of new snow, loading, and changes in temperature. Large avalanches mostly initiate from the alpine but have a potential to run through all elevation bands.

Don't forget to post avalanche observations to the MIN.

Snowpack Summary

Top 20 to 40cm of low density facetted crystals in sheltered areas. There is extensive wind effect at tree line and above from previous SW winds with a dash of reverse loading happening from the recent light easterly winds.

This is sitting on top of a generally weak mid and lower snowpack. Facets and depth hoar linger at the base of the snowpack with the height of snow varying from 60 to 160cm.

Weather Summary

Monday and Tuesday forecast is calling for cold temperatures and light winds. Alpine highs around -10C to -15C. Freezing level at valley bottom.

Detailed weather forecasts from Avalanche Canada: https://www.avalanche.ca/weather/forecast

Terrain and Travel Advice

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Wind Slabs

An icon showing Wind Slabs

Previous moderate to strong winds from the SW have formed wind slabs in usual lees, but recent light easterly winds have a potential for reverse loading. While assessing recent wind affect, keep in mind the potential of triggering either older wind slabs below or deep instabilities at the bottom of the snowpack, especially in thin to thick zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Although natural avalanche activity has slowed down and snowpack test results are less conclusive on this layer, skier triggering is still possible.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Mar 6th, 2023 4:00PM