Avalanche Forecast
Issued: Feb 3rd, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
mconlan,
Avalanche Canada
A powerful storm is rapidly increasing avalanche danger. An avalanche cycle is expected over the coming days, especially where the snow is loading a buried weak layer.
Summary
Confidence
High - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather.
Weather Forecast
THURSDAY NIGHT: Cloudy with snowfall, accumulation 5 to 15 cm, 20 to 40 km/h southwest wind, alpine temperature -8 C.
FRIDAY: Cloudy with snowfall, accumulation 5 to 15 cm, 40 to 60 km/h southwest wind, alpine temperature -7 C.
SATURDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 40 to 60 km/h west wind, alpine temperature -6 C, freezing level rising to 1300 m.
SUNDAY: Mix of sun and cloud with no precipitation, 30 to 50 km/h southwest wind, alpine temperature -2 C, freezing level rising to 1800 m.
Avalanche Summary
A few small loose avalanches were observed out of steep terrain on Wednesday.
Natural and rider-triggered avalanche activity is expected to spike during Friday and into the weekend. Large avalanches are expected in areas where the buried surface hoar described in the Snowpack Summary exists. Avoidance of avalanche terrain is your best bet for having a safe day.
Snowpack Summary
Much of the region is forecast to get around 20 to 30 cm of snow over Friday, with locally higher amounts possible. The snow will rapidly build new slabs and create touchy avalanche conditions. In wind-exposed terrain, new wind slabs will rapidly form from strong wind. In sheltered terrain, the snow will form new storm slabs.
The snow will load a weak layer of surface hoar crystals found around 50 to 80 cm deep by the end of Friday. We've received indication that the surface hoar is likely most prominent in sheltered openings at and below treeline (e.g., open trees, cutblocks, burns) but could extend into wind-sheltered terrain in the alpine. On south aspects, a melt-freeze crust may exist instead of surface hoar.
The lower snowpack is generally strong and well-bonded.
Terrain and Travel
- Travel in alpine terrain is not recommended.
- Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Watch for fresh storm slabs building throughout the day.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Problems
Persistent Slabs
New snow is loading a widespread weak layer of surface hoar crystals. The layer may be found around 40 to 80 cm deep and is most prominent in areas sheltered from the wind at and below treeline. Example terrain features to particularly treat as suspect include the lee side of ridges, openings in trees, cut blocks, and burns.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
As the snow accumulates, new slabs will build. Expect to find storm slabs in sheltered areas and wind slabs in wind-exposed terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 4th, 2022 4:00PM
