Avalanche Forecast
Issued: Feb 23rd, 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
Wind slabs may be found on all aspects. The consequence of any incident in cold weather could be serious.
Summary
Confidence
Moderate
Avalanche Summary
Many small to large (size 1 to 2.5) wind slabs were triggered naturally and by riders on Wednesday. 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 observed, which likely occurred from rapid snow loading with strong wind over the past few days.
Looking forward, the cold weather may mean that wind slabs could remain human-triggerable for the coming days.
Snowpack Summary
Northeast wind produced touchy wind slabs in lee terrain features in wind-exposed terrain. The wind is switching to the southwest, which may form new wind slabs in lee terrain features. This means that wind slabs may be found on all aspects. These slabs may remain reactive for a few more days due to frigid weather limiting bonding.
A small layer of surface hoar crystals may be found below the 50 to 100 cm of storm snow from the past week, particularly in areas sheltered from the wind around treeline.
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
Thursday Night
Clear skies with no precipitation, 10 to 20 km/h northeast wind, treeline temperature -23 °C.
Friday
Increasing clouds with no precipitation, 20 to 40 km/h southwest wind, treeline temperature - 21 °C.
SaturdayCloudy with snowfall, accumulation 5 to 10 cm, 20 to 40 km/h south wind, treeline temperature -15 °C.
SundayCloudy with snowfall, accumulation 5 to 15 cm, 20 to 30 km/h southwest wind, treeline temperature -14 °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.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- 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
The wind will shift from the northeast to the southwest, meaning wind slabs may be found on all aspects in wind-exposed terrain. Travel conservatively and assess for slab development prior to committing to high-consequence terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
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 24th, 2023 4:00PM
