Avalanche Forecast
Issued: Jan 24th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
zryan,
Avalanche Canada
Dangerous avalanche conditions exist in this region. Wind and warming will continue to test a fragile snowpack. Read more in our latest forecaster blog.
Summary
Confidence
Avalanche Summary
No new avalanches were reported in the past few days in the region but observations are limited.
Looking forward to this week, reactive wind slabs will continue to form but concern for step-down and large natural and human-triggered deep persistent slab avalanches is at the forefront of our minds. It is uncertain when the "tipping point" for large destructive avalanches will be reached, and this uncertainty demands conservative and low-consequence terrain selection. Check out this video on incremental loading to learn more.
If you are out in the backcountry please consider filling out a Mountain Information Network report.
Snowpack Summary
Strong westerly winds will continue to affect wind-exposed terrain and build fresh wind slabs in lee areas. On steep solar aspects, and sun crust may exist and at lower elevations, a rain crust exists.
Snowpack depths are shallower than normal, and several buried weak layers have been a concern over the past few weeks. Surface hoar or crust layers in the mid-snowpack may exist in this region, but field observations suggest these mid-snowpack weaknesses are less prominent here than in other areas.
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 to be problematic in steep, rocky alpine terrain, where shallower wind slab avalanches can scrub down to these basal facets.
Weather Summary
Tuesday night
A mix of sun and cloud with isolated flurries. Alpine temperatures rise to -4 C. Ridge wind northwest 40-70 km/h. Freezing level rises to 1500 m.
Wednesday
A mix of sun and cloud with isolated flurries. Alpine temperatures rise to -1 C. Ridge wind northwest 50-80 km/h. Freezing level rises to 1800 m.
Thursday
A mix of sun and cloud. Ridge wind northwest 40-80 km/h. Freezing level 1500 m.
Friday
Mainly cloudy with flurries, up to 10 cm of accumulation. Alpine temperatures drop to -8 C. Ridge wind northwest 15-40 km/h. Freezing level drops to 500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- 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.
- Avoid all avalanche terrain during periods of strong wind.
Problems
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.
Avoid thin and rocky start zones where weak layers sit closer to the surface, 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.
Remote triggering is a concern for this layer, avoid travelling below steep slopes.
The likelihood of avalanches will increase as wind-transported snow and warming temperatures add load to a fragile snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Strong to extreme westerly winds will redistribute the surface snow, stripping windward areas and creating deep deposits of wind slab in lee terrain features. Due to the strength of these winds, wind slabs may be found in more atypical locations such as at lower elevations, low down in start zones or pressed into broad gully features.
Be extremely cautious around wind-loaded areas, as wind slabs may be reactive to rider triggering and have the very real potential of stepping down to deeper instabilities creating large and consequential avalanches.
Aspects: North, North East, East, South East, South, North West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 25th, 2023 4:00PM
