Avalanche Forecast
Issued: Dec 21st, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Timothy Johnson,
Watch for the avalanche danger to rise on Wednesday with the incoming storm.
Expect travel delays on the Icefields Parkway Thursday due to avalanche control. Check AB511 for updates.
Summary
Weather Forecast
Wednesday
Periods of snow.
Accumulation: 14 cm.
Alpine temperature: High -8 °C.
Ridge wind southwest: 20 km/h gusting to 45 km/h.
Freezing level at valley bottom.
Thursday
Flurries.
Accumulation: 10 cm.
Alpine temperature: Low -16 °C, High -7 °C.
Ridge wind west: 15 km/h gusting to 45 km/h.
Freezing level at valley bottom.
Snowpack Summary
Recent snow has been redistributed by variable winds creating fresh wind slab in the alpine and on exposed terrain features at treeline. The mid snowpack has settled well with a deteriorating rain crust present up to 1950m. Cold temperatures and a crust/facet layer near the base of the snowpack continues to promote basal faceting.
Avalanche Summary
Two size 1 wind slab avalanches were triggered by explosive avalanche control on Sunday in the Parkers ridge area. Avalanches occurred on cross loaded, alpine features below ridge top. No recent natural avalanche activity observed.
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Confidence
Problems
Wind Slabs
Increasing winds and new snow overnight and through the day on Wednesday will create new wind slabs in lee features.
- Use caution in lee and cross-loaded terrain near ridge crests.
- Watch for stiffer feeling snow. Avoid areas that appear wind loaded.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
This problem is trending toward unreactive but our current snowpack structure means this layer could wake up with a large trigger or rapid loading. Use extra caution in thin areas were humans are most likely to trigger this high consequence layer.
- Use caution in thin snowpack areas.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Dec 22nd, 2021 4:00PM
