Avalanche Forecast
Issued: Feb 6th, 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.
ldreier,
Avalanche Canada
It is uncertain how reactive the recently buried weak layer is to human triggers. Once triggered, it will likely result in a large avalanche that can have serious consequences. This uncertainty is best managed with conservative terrain choices.
Summary
Confidence
Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.
Weather Forecast
SUNDAY NIGHT: Clear with increasing clouds, up to 3 cm new snow, moderate south wind, alpine temperature 0 C, freezing level at 2100 m and slowly dropping to 1500 m.Â
MONDAY: Mostly cloudy, 5 to 10 cm new snow, light to moderate west wind, alpine temperature -3 C, freezing level 1500 m.
TUESDAY: Mostly cloudy, up to 5 cm new snow, light to moderate southwest wind, alpine temperature -4 C, freezing level 1500 m.Â
WEDNESDAY: Cloudy, 5 to 10 cm new snow, light to moderate west wind, alpine temperature 0 C, freezing level rising to 2300 m.Â
Avalanche Summary
On Sunday, two natural large avalanches of size 2-2.5 were observed in steep terrain on north and east aspects in the alpine.Â
On Saturday, several storm and wind slab avalanches up to size 2.5 were observed at treeline and in the alpine. Most released naturally, and a couple were likely triggered by riders.
Observations on Friday were limited due to bad visibility. A natural avalanche cycle of small storm slab avalanches up to size 1.5 was reported.
Snowpack Summary
The recent storm brought around 30 to 50 cm of snow. The snow formed storm slabs in sheltered areas and wind slabs in lee terrain features from strong southwest wind. These slabs will remain touchy with temperatures staying warm overnight Sunday to Monday.Â
The snow will be particularly touchy where it loaded a weak layer of surface hoar crystals. This layer is likely anywhere from 50 to 100 cm deep. Reports suggest that the surface hoar is most prominent in sheltered openings at and below treeline but could extend into wind-sheltered terrain in the alpine. Example terrain features to treat as suspect include the lee side of protected ridges, openings in the trees, cut blocks, and burns. 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
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Persistent Slabs
The recent snow loaded a widespread weak layer of surface hoar crystals. The layer may be found around 50 to 100 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.
The buried weak layer was reported to be very active in the Blue River area at all elevations and is present up to treeline in the Wells Gray area, Mica Mountain and around Valemount.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
The recent storm brought 30 to 50 cm new snow which has formed slabs. Warm temperatures will further promote slab development. Expect to find storm slabs in sheltered areas and wind slabs in wind-exposed terrain from strong southwest wind.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 7th, 2022 4:00PM
