Avalanche Forecast
Issued: Mar 9th, 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.
rgoddard,
Avalanche Canada
Enjoy the snow but be alert when transitioning into wind-affected terrain.
Avoid steep, rocky, and shallow snowpacks to lessen your chance of triggering buried weak layers.
Summary
Confidence
Moderate
Avalanche Summary
On Thursday, the results of a natural cornice failure were observed in the Core Lodge area. It was on a rocky northeast aspect and it did not produce an avalanche on the slope below and was thought to be about 24 hours old.
Last weekend, there were several natural and human-triggered wind slabs were observed from a variety of aspects in alpine and treeline terrain as northeasterly winds impacted the region. Check out this MIN from Pine Pass on Saturday for an example.
Another MIN report from Pine Pass on Sunday shows a very large deep persistent slab from alpine terrain that was likely triggered by a cornice failure or wind-loading. This is the first observation in several weeks of deep persistent slab activity and is an indication that this layer should be on our radar, particularly in the shallower snowpack parts in the region.
Snowpack Summary
Shifting winds have redistributed any available snow into wind slabs on a variety of aspects. There is a good chance that the wind has stripped the snow away in the alpine and wind slabs could be found at treeline. In sheltered areas, soft storm snow from last week can be found and will be resting on heavily wind-affected snow. This MIN has some great photos showing this.
The middle of the snowpack is generally strong.
A weak layer of large and weak facets is found near the base of the snowpack. This layer is of greatest concern in shallow snowpack areas in the north and east of the region.
Weather Summary
Thursday Night
Clear with increasing clouds, no accumulation, winds southeast 20 km/h, treeline temperatures around -10 °C.
Friday
Cloudy with sunny periods, trace accumulation, winds northeast 15 km/h ramping up to 45 by afternoon, treeline temperatures around -15 °C.
Saturday
Cloudy with sunny periods late in the day, trace accumulation, winds easterly 15 to 25 km/h gusting to 40, treeline temperatures -20 to -15 °C.
Sunday
Cloudy with sunny periods, trace accumulation, winds easterly 20 to 30 km/h gusting to 40, treeline temperatures around -10 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
- Minimize exposure to sun-exposed slopes when the solar radiation is strong.
Problems
Wind Slabs
Variable winds that have reached all elevations may have created wind slabs on all aspects as far down in elevation as below treeline.
In many areas, the wind has scoured the alpine of snow so it will be at treeline where you may encounter the most reactive wind slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. Large triggers such as smaller avalanches in motion or cornice failures have the potential to produce very large avalanches with wide propagation. Suspect terrain for human triggering includes steep, shallow and rocky terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 10th, 2023 4:00PM
