Avalanche Forecast
Issued: Feb 16th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Deep Persistent Slabs.
Timothy Johnson,
The Tonquin Area is officially open for winter travel. Use caution as this is typically more shallow and therefore a weaker snowpack.
Summary
Weather Forecast
Wednesday: A mix of sun and cloud. Alpine temperature: High -13 C. Ridge wind NW: 10 km/h.
Thursday: A mix of sun and cloud. Alpine temperature: Low -16 C, High -12 C. Ridge wind southwest: 10 km/h.
Friday: A mix of sun and cloud with isolated flurries. Precipitation: Trace. Alpine temperature: Low -16 C, High -10 C. Ridge wind SW: 15-35 km/h.
Snowpack Summary
Moderate to strong SW winds and higher humidity are likely creating wind slabs in the alpine on 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
On Sunday one sz 3 avalanche (wind slab) observed from extreme, alpine, north aspect terrain. No other avalanches observed.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
Moderate to strong SW winds in the alpine and higher RH values are likely creating wind slabs.
- Travel on ridgetops to avoid wind slabs on slopes below.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
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
Expected Size
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
Expected Size
Valid until: Feb 17th, 2021 4:00PM
