Avalanche Forecast

Issued: Feb 17th, 2021 4:00PM

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

Garth Lemke,

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The Tonquin Area is officially open for winter travel. Use caution as this area is typically more shallow and therefore a weaker snowpack. Be vigilant for shallow locations being human trigger spots.

Summary

Weather Forecast

Thursday will be a mix of sun and cloud, -12 C and light SW winds.  Friday will bring sun and cloud with isolated flurries, -10 C, and light gusting moderate SW winds.

Snowpack Summary

Moderate to strong SW winds and higher humidity continue to create wind slabs in high alpine lee features. The upper snowpack has facetted from the recent cold temperatures and overlies a supportive mid-pack, except in shallow areas where the entire snowpack is weak and facetted.

Avalanche Summary

Wednesday's patrol was cut short due to a rescue. Nothing new was noted or reported.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Moderate to strong SW winds in the alpine and higher RH values are likely creating wind slabs.

  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
  • Travel on ridgetops to avoid wind slabs on slopes below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

An icon showing Loose Dry

The likelihood of triggering increases with warming temperatures and solar input. Isolated, sheltered features that have not been impacted by winds are susceptible to sluffing and loose dry avalanches. Ice climbers be aware of these features.

  • Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 1.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Caution in thin snowpack areas where triggering is more likely. This is a low probability but high consequence problem.

  • Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 3

Valid until: Feb 18th, 2021 4:00PM