Avalanche Forecast
Issued: Mar 12th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs, Storm Slabs and Loose Wet.
swerner,
Avalanche Canada
Natural avalanche activity could spike on slopes facing the sunRider and remote triggering of large avalanches are an ongoing concern. Choose conservative, low consequence terrain.
Summary
Confidence
Moderate
Avalanche Summary
The region saw lots of avalanche activity on Monday. Very large natural persistent slab avalanches and numerous human-triggered continue to be reported up to size 3. There were also many size 1-2 natural and human-triggered storm and wind slabs failing in the upper snowpack. Most were reported from 1800 m and above, but all aspects showed reactivity.
Ongoing natural, rider and remotely triggered avalanches persist on this layer. Avoid solar slopes when the sun is out.
Snowpack Summary
Tuesday morning saw 10-20 cm of new snow, bringing recent storm snow totals 40 to 60 cm across the region. The new snow sits on sun crusts and wind-affected snow from previous strong southwest winds. Below this, two layers of surface hoar and sun crust can be found in the top meter of the snowpack. One from late February and the other from early March.
A thick and hard widespread crust formed in early February is buried about 80 to 150 cm deep. This crust has a layer of facets above it in many areas and has been reactive to human triggering.
The snowpack below this crust is generally not concerning except in shallow alpine terrain.
Weather Summary
Tuesday Night
Mostly cloudy with 5 to 15 cm of new snow. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -7°C. Freezing levels valley bottom.
Wednesday
Mix of sun and cloud. 10 to 20 km/h southwest ridgetop wind. Treeline temperatures near -5°C. Freezing level rising to 1500 m.
Thursday
A mix of sun and cloud. 10 to 20 km/h northwest ridgetop wind. Treeline temperatures near -1°C. Freezing level rising to 1700 m.
Friday
Sunny. 15 to 30 km/h northwest ridgetop wind. Treeline temperatures near 0°C. Freezing level rising to 2500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Conservative terrain selection is critical, choose only well supported, low consequence lines.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
- Storm slabs in motion may step down to deeply buried weak layers resulting in very large avalanches.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
Problems
Persistent Slabs
A weak layer of faceted grains above a crust buried 80 to 150 cm deep is a recipe for large, high-consequence avalanches. Remote triggering is an ongoing concern and means the layer is still primed for human triggering.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
Storm slabs may release on weak layers from late Febuary and early March resulting in larger avalanches. There is also concern for these avalanches stepping all the way down to the early Febuary layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Wet loose avalanches are likely on solar aspects if the sun is out. Watch for natural avalanches, pinwheeling/ snowballing and moist snow surfaces. This indicates an unstable upper snowpack.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 13th, 2024 4:00PM
