Avalanche Forecast
Issued: Mar 8th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs, Persistent Slabs and Wind Slabs.
IJ,
Avalanche Canada
We've noticed several cornice failures over the last few days. These are likely triggered by solar radiation and generally triggering large avalanches on the slopes below.
As fresh lines become scarce, resist the urge to step into bigger terrain.
Summary
Confidence
Moderate
Avalanche Summary
Although avalanche activity is tapering, we are still seeing daily natural and explosive triggered avalanches. On Wednesday, field teams near Bow Lake observed a size 3 natural on a NW cross loaded aspect in the alpine that initiated as a windslab and stepped down to deeper layers.
LL ski hill triggered a size 2.5 on a reloaded bed surface for the 3rd time this season in steep alpine east facing terrain.
Likely triggers for natural avalanches are cornice failures and solar radiation and possibly both.
Snowpack Summary
Alpine and exposed treeline areas are wind effected with wind slabs that are slowly becoming less reactive. Steep solar slopes at treeline and below have a thin sun crust. The various Jan PWL interfaces of sun crusts, facets, and surface hoar are now down 40-80 cm. The weaker Nov. 16 basal facet layer is down 50-120 cm and produces moderate to hard sudden collapse results in tests.
Weather Summary
Stable weather continues on Thursday before a small system moves in on Friday. Consistent diurnal temperature swings with lows near -20, highs to -5 throughout the period.
Thursday: Clear and calm.
Friday: Snow starting near noon. 2- 5 cm with moderate NE alpine winds.
Saturday: Clearing with light NW winds.
For a more detailed weather forecast, click here.
Terrain and Travel Advice
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Deep Persistent Slabs
Weak facets and depth hoar are present at the bottom of the snowpack and inspire little confidence. Be especially cautious in thin snowpack areas, which are likely areas for triggering. Watch for cornice failures triggering this layer, which will be more likely if the sun is out in the afternoon.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Three persistent weak layers formed in January are down 40-80 cm. The biggest concern is triggering these buried suncrusts on steep solar slopes, but weaker facets and isolated surface hoar can be found at the same interfaces on shaded aspects.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Isolated windslabs still exist in alpine areas and may be a trigger for the deeper layers.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 9th, 2023 4:00PM
