Avalanche Forecast
Issued: Dec 14th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
zryan,
Avalanche Canada
Northerly winds have formed wind slabs in unusual areas and at lower elevations than you might typically expect. These slabs are expected to bond poorly to the underlying crust.
Keep in mind that if triggered, wind slabs have the potential to 'step down' to the weak lower snowpack, creating larger than expected avalanches.
Summary
Confidence
Avalanche Summary
No new avalanches have been reported in the past few days at the time of publishing this forecast.
Looking forward to Thursday, northerly winds are expected to redistribute the surface snow into fresh wind slabs anywhere it remains loose and powdery.
Observations are limited this time of year. Please keep posting your observations to the MIN; it helps strengthen our information gathering.
Snowpack Summary
In deeper zones near ridges, the snowpack is around 120 to 170 cm, which is low for early December. Alpine terrain in windy areas is scoured and bare.
Surface: Large surface hoar has grown on the surface in many areas. A sun crust exists on steep solar aspects. Boot top powder in deep areas. Same old crusts, facets, and rocks on wind-scoured slopes.Upper-pack: In sheltered areas below the fresh snow is well-developed surface hoar. Generally, there's 40 to 70 cm of low-density and faceting (aka weak) snow in the upper pack.Mid-pack: November crust, with a layer of soft facets above. This is the primary weak layer, found pretty much halfway down.Lower-pack: a mixture of old crusts and facets but some suggest that these layers are a bit harder or stronger than what's found in other regions (e.g. Duffy or Hurley).
Weather Summary
Wednesday night
Clear with cloudy periods. Alpine temperatures drop to a low of -6 °C. Ridge wind north 15 km/h gusting to 45 km/h. Freezing level at valley bottom.
Thursday
Sunny with cloudy periods. Alpine temperatures reach a high of 0 °C. Ridge wind north 20 km/h gusting to 55 km/h. Freezing level rises to 1700 metres.
FridaySunny with cloudy periods and an alpine temperature inversion. Alpine temperatures reach a high of -1 °C. Ridge wind west 10-25 km/h. Freezing level rises to 2500 metres.
SaturdayCloudy with sunny periods and isolated flurries. Alpine temperatures reach a high of -5 °C. Ridge wind southwest 15 km/h gusting to 65 km/h. Freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs may be poorly bonded to the underlying crust.
- The best and safest riding will be on slopes that have soft snow without any slab properties.
Problems
Wind Slabs
Northerly winds are expected to form fresh, reactive wind slabs in the alpine and treeline. These slabs are expected to form on southerly aspects and may bond poorly to the underlying crust.
With the sugary, faceted, and weak snowpack wind slabs could step down to the middle of the snowpack, resulting in larger than expected avalanches.
Aspects: East, South East, South, South West, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 15th, 2022 4:00PM
