Avalanche Forecast
Issued: Feb 24th, 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
Avalanche hazard will rise over the day as new slabs form.
Summary
Confidence
Avalanche Summary
Many small to large (size 1 to 2.5) wind slabs were triggered naturally and by riders over the past few days. They mostly occurred on south to west aspects at alpine elevations. A few very large (size 3.5 to 4) deep persistent slab avalanches were also observed over the week, which likely occurred during very windy conditions.
Looking forward, both new and old wind slabs could be human-triggered on Saturday, so use particular caution on any steep wind-exposed slope.
Snowpack Summary
Stormy conditions return, bringing snow and strong southwest wind. New wind slabs will form, which will rest on previously formed wind slabs from strong northeast wind. This means that wind slabs may be found on all aspects.
A small layer of surface hoar crystals may be found about 50 to 100 cm deep, particularly in areas sheltered from the wind around treeline. This layer is likely starting to bond to the snowpack.
Large and weak facets that formed in November are found near the base of the snowpack. Although the likelihood of triggering this layer is low at this time, the consequence of doing so would be high. This layer is most likely to be human-triggered in thin, rocky slopes at alpine and upper treeline elevations.
Weather Summary
Friday Night
Cloudy with snowfall, accumulation 2 to 5 cm, 20 to 40 km/h southwest wind, treeline temperature - 19 °C.
Saturday
Cloudy with snowfall, accumulation 10 to 20 cm with local enhancement possible, 30 to 50 km/h south wind, treeline temperature -14 °C.
SundayCloudy with snowfall, accumulation 5 to 15 cm, 20 to 30 km/h southwest wind, treeline temperature -14 °C.
MondayMostly cloudy with isolated snowfall, accumulation 1 to 3 cm, 20 km/h south wind, treeline temperature -14 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for avalanche hazard to increase throughout the day.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Problems
Wind Slabs
Stormy conditions return on Saturday, which may form new wind slabs in lee terrain features. Strong wind over the past week formed wind slabs on all aspects and at all elevations. Assess for slab development prior to committing to high-consequence terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets is found near the base of the snowpack, particularly at alpine and treeline elevations. The layer is deeply buried, meaning the likelihood of human triggering is low. Suspect terrain for human triggering includes steep, thin, shallow, and rocky terrain, which is often found near ridgelines.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 25th, 2023 4:00PM
