Avalanche Forecast
Issued: Mar 16th, 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
Warm temperatures and solar radiation will begin to affect the snowpack.
Don't let good riding lure you into high-consequence terrain, especially during the warmest part of the day.
Summary
Confidence
Avalanche Summary
On Wednesday there were several storm slab avalanches, up to size 2, reported. Of note, some of these were accidentally and remotely triggered. These occurred predominantly on northerly aspects and at all elevations. They released at a depth of 30 to 40 cm and on a surface hoar/crust combo that was buried on March 11th. There is a good chance of more avalanches similar to these out there.
Snowpack Summary
Moderate southerly and westerly winds have redistributed the 20 to 30 cm of recent snow and may have created wind slabs that will remain reactive to human triggers. The sun and warm temperatures are beginning to make their mark on the snowpack. On solar aspects and at lower elevations the top layer of snow may become moist in the afternoons and frozen in the mornings.
Below the new snow are a variety of surfaces. These include surface hoar, 3 to 10 mm, on shady slopes at all elevations, wind-affected surfaces at treeline and above, and sun crust on sunny aspects. These layers are likely to create problems in the future.
The mid-snowpack is generally strong but the lower snowpack is a different story.
The November facets are still prominent at the base of the snowpack. They are showing signs of improving but this layer remains a significant concern in rocky, shallow, or thin to thick snowpack areas at treeline and above.
Weather Summary
Thursday Night
Clear, no accumulation, winds southerly 15 to 25 km/h, treeline temperatures -8 to -4 °C with freezing levels dropping to valley bottom.
Friday
Sunny, no accumulation, winds southeast 15 to 25 km/h, gusting to 30, treeline temperatures -5 to 0 °C with freezing levels getting up to 1700 m.
Saturday
Mostly sunny, no accumulation, winds southerly 20 to 30 km/h, treeline temperatures -5 to 0 °C with freezing levels getting up to 1700 m.
Sunday
A mix of sun and cloud, no accumulation, winds southerly 10 to 15 km/h, freezing levels to 1800 m.
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.
- Use small low consequence slopes to test the bond of the new snow.
- Avoid exposure to slopes that have cornices overhead.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
Problems
Wind Slabs
Moderate westerly winds may have redistributed the 20 to 30 cm of recent creating reactive wind slabs at higher elevations.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 17th, 2023 4:00PM
