Avalanche Forecast
Issued: Jan 30th, 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.
mconlan,
Avalanche Canada
Assess for wind slabs in steep terrain and remember that a small avalanche could step down to deeper weak layers.
Summary
Confidence
Moderate
Avalanche Summary
No new avalanches were observed on Sunday. Many wind slab avalanches were triggered by riders and naturally on Saturday. They occurred on all aspects.
Looking forward, riders may trigger wind slab avalanches in wind-exposed terrain as we receive new snow and strong wind. Smaller avalanches could step down to the facets near the base of the snowpack, producing very large avalanches. See more on the potential of triggering deeper weak layers Forecasters' Blog.
Please continue to send in your observations through the MIN.
Snowpack Summary
New snow and strong wind may form new wind slabs in lee terrain features in wind-exposed terrain. The snow will rest on previously wind-affected snow. A melt-freeze crust is found near the snow surface on sun-exposed slopes and everywhere below 1600 m.
Several crust/facet/surface hoar layers exist in the upper and middle portions of the snowpack. Recent observations suggest these layers are not as concerning as in neighbouring regions.
The most concerning layer is at the base of the snowpack from large and weak facets formed in November. This layer is widespread and most likely problematic in steep, rocky alpine terrain.
Weather Summary
Monday Night
Cloudy with snowfall, accumulation 5 to 10 cm with local enhancements possible, 20 to 40 km/h west wind, treeline temperature -12 °C.
Tuesday
Cloudy with snowfall, accumulation 5 to 10 cm with local enhancements possible, 30 to 50 km/h west wind, treeline temperature -12 °C.
WednesdayCloudy with snowfall, accumulation 5 to 10 cm, 20 km/h southwest wind, treeline temperature -15 °C.
ThursdayCloudy with snowfall, accumulation 5 to 10 cm, 30 km/h southwest wind, treeline temperature -9 °C.
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
New snow and strong wind may form new wind slabs on Tuesday. Wind direction has varied, producing wind slabs on all aspects.
Aspects: All aspects.
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 is most prominent in upper treeline and lower alpine elevations. As snow accumulates, the likelihood of natural and human-triggered avalanches increases. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain, or by triggering a smaller avalanche that could step down to this layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 31st, 2023 4:00PM
