Avalanche Forecast
Issued: Feb 21st, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
mconlan,
Avalanche Canada
New wind slabs are likely forming up high. Use added caution on steep slopes in open trees as a slab of snow may rest on surface hoar, particularly in the eastern part of the region.
Summary
Confidence
Weather Forecast
FRIDAY NIGHT: Increasing clouds, moderate to strong southwest wind, alpine temperature -5 C.
SATURDAY: Mix of sun and cloud with isolated flurries, accumulation 1 to 3 cm, moderate west wind, alpine temperature -5 C, freezing level 1300 m.
SUNDAY: Cloudy with snowfall, accumulation 5 to 10 cm, moderate southwest wind, alpine temperature -6 C, freezing level 900 m.
MONDAY: Morning snowfall and afternoon clearing, accumulation 2 to 5 cm, light to moderate northwest wind, alpine temperature -7 C, freezing level 1000 m.
Avalanche Summary
A few slab avalanches were triggered by skiers on Thursday. They were both on northerly aspects. One of them was a wind loaded feature and the other was suspected to have failed on the weak layer described in the snowpack summary, with a slab depth of about 30 cm.
Snowpack Summary
A dusting of snow is forecast for Saturday, along with strong southwest wind. New wind slabs are likely to form in lee terrain features. The new snow will accumulate onto a widespread layer of feathery surface hoar crystals or a melt-freeze crust on southerly aspects.
A 20 to 30 cm thick slab has been reactive to human traffic since last weekend, where the snow overlies a weak layer of surface hoar. The slab has been most reactive in open trees in the eastern part of the region.
The remainder of the snowpack is well-settled.
Terrain and Travel
- Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
Strong southwest wind and a dusting of new snow will form new wind slabs in lee terrain features near ridges.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A 20 to 30 cm slab has been reactive to riders in the past week. The slab has been touchiest in open trees in the east of the region, where the slab rests on a layer of weak and feathery surface hoar crystals. The spatial distribution of the surface hoar layer is unclear and may be spottier in the west of the region.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 22nd, 2020 5:00PM
