Avalanche Forecast
Issued: Jan 29th, 2023 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.
trettie,
Avalanche Canada
Use caution as you gain elevation. Deeper layers are most likely to be triggered at upper treeline/lower alpine.
Read more in the latest Forecaster Blog.
Summary
Confidence
Moderate
Avalanche Summary
No new avalanches were reported in the past couple days in the region.
A Thursday report identified a size 2.5 avalanche on a northeast slope, triggered by a cornice failure.
An ongoing concern for step-down and large natural and human-triggered deep persistent slab avalanches is at the forefront of our minds. Check out this video on incremental loading to learn more.
Please continue to send in your observations through the MIN.
Snowpack Summary
Recent storm snow has been redistributed into wind slabs on southerly aspects in the alpine. This new snow rests over a crust on solars and all aspects below 1600m.
Snowpack depths are shallower than normal resulting in a weaker snowpack. Several crust/facet layers exist in the upper and mid snowpack. It is also possible to find small surface hoar crystals at these interfaces. Recent observations suggest these layers are not as concerning as further south.
The most concerning layer in this area is at the base of the snowpack. Large, weak facets buried in November are widespread. This layer is most likely problematic in steep, rocky alpine terrain, where shallower wind slab avalanches can scrub down to these basal facets.
Weather Summary
Sunday Night
Cloudy with no new snow expected. Strong north to northwest winds and a low of -25 at 1800m.
Monday
Mostly cloudy with around 5cm of new snow expected. Strong northwest winds and a high of -13 at 1800m, possible temperature inversion with colder temps lower in valleys.
Tuesday
Stormy with 5 to 15cm of new snow expected. Moderate to strong west winds with a high of -12 at 1800m.
Wednesday
Cloudy with 5 to 10cm of new snow expected. Light to moderate west winds and a high of -20 at 1800m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Wind Slabs
Northerly winds have formed wind slabs on southerly aspects and cross loaded others.
Be aware that wind slab avalanches could step down to deeper layers.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer has most recently been problematic in upper treeline/lower alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow previously undisturbed terrain, or by first triggering a layer further up in the snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 30th, 2023 4:00PM
