Avalanche Forecast
Issued: Feb 20th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
zryan,
Avalanche Canada
Avoid wind-loaded areas. Fresh reactive wind slabs are expected to form throughout the day as northeasterly winds redistribute yesterday's storm snow.
Summary
Confidence
Avalanche Summary
Stormy weather has limited observations in the past few days, but evidence of a natural storm and wind slab cycle has been observed throughout the region. One notable skier accidental size 2 storm slab occurred in the Shames backcountry on Sunday. See details in the MIN report.
Looking forward to Tuesday, we expect fresh, reactive wind slabs to form in a reverse loading pattern and at lower elevations than you might typically expect. These wind slabs may be particularly reactive where they overlie a crust.
Snowpack Summary
Up to 40 cm of new snow has accumulated in the past 2 days. Northeasterly winds are expected to redistribute this new snow into fresh, reactive wind slabs. This new snow overlies last week's 60cm of storm snow and wind-affected surfaces in exposed areas.
Up to 80cm now sits over a layer of small surface hoar, facets and wind-affected surfaces. Below treeline, a new crust could exist up to 1000m.
A layer of facets and a crust from late January can be found down 100 to 200cm. Below this layer, the snowpack is generally well-settled and right-side up.
Weather Summary
Monday night
Cloudy with clear periods and flurries, trace to 10 cm of accumulation. Alpine temperatures drop to a low of -8 °C. Ridge wind northeast 25-50 km/h. Freezing level at valley bottom.
Tuesday
A mix of sun and cloud. Alpine temperatures reach a high of -9 °C. Ridge wind northeast 25 km/h gusting to 50 km/h. Freezing level at valley bottom.
Wednesday
Sunny. Alpine temperatures reach high of -14 °C. Ridge wind northeast 25 km/h gusting to 60 km/h. Freezing level at valley bottom.
Thursday
Sunny with cloudy periods. Alpine temperatures reach a high of -16 °C. Ridge wind east 25 km/h gusting to 50 km/h. Freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
- Keep your guard up at lower elevations. Wind slab formation has been extensive.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
Problems
Wind Slabs
Northeasterly winds will redistribute 30-50 cm of recent new snow into fresh, reactive wind slabs. These slabs will form in a reverse loading pattern and at lower elevations than you might typically expect. Wind slabs may be particularly reactive where they overlie a crust.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 21st, 2023 4:00PM
