Avalanche Forecast
Issued: Jan 19th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
mconlan,
Avalanche Canada
Assess for wind slabs in steep terrain near ridges.
Summary
Confidence
Moderate
Avalanche Summary
Wind slabs were triggerable by riders on Thursday at higher elevations. On Wednesday, many small to large (size 1 to 2) storm slab and dry loose avalanches were triggered by riders and naturally within the 30 to 60 cm of snow from Tuesday night.
Looking ahead, riders could trigger wind slabs in lee terrain features where wind has redistributed the storm snow. It also remains possible that riders could trigger storm slabs in sheltered areas, particularly if all the recent storm snow has a poor bond to the underlying melt-freeze crust.
Snowpack Summary
Around 5 to 15 cm of snow is forecast to accumulate by Friday afternoon along with southwest wind. This snow builds on the 30 to 60 cm of snow that accumulated Tuesday night with strong wind. Wind slabs are found near ridges in wind-exposed terrain. All this snow is consolidating in areas sheltered from the wind, which may take a bit of time to bond to a hard melt-freeze crust found below 1500 m.
Snowpack depths at treeline are around 100 cm, tapering quickly with elevation. Although the snowpack in most forested areas below treeline remains below threshold depths for avalanches, many steep bluffs, cut-banks, and alpine-like features in the upper below treeline band are capable of producing avalanches.
Weather Summary
Thursday Night
Cloudy with snowfall, accumulation 5 to 10 cm, 30 km/h southwest wind, treeline temperature -3 °C, freezing level 800 m.
Friday
Cloudy with snowfall, accumulation 2 to 5 cm, 20 to 30 km/h west wind, treeline temperature -1 °C, freezing level rising to 1300 m.
SaturdayCloudy with snowfall then clearing, accumulation 15 to 25 cm, 80 km/h southwest wind, treeline temperature -1 °C.
SundayMix of sun and cloud with no precipitation, 30 km/h northwest wind, treeline temperature -2 °C.
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.
- Closely monitor how the new snow is bonding to the crust.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Problems
Wind Slabs
Wind slabs have formed in lee terrain features from all the recent snow. Assess for slabs prior to committing to large terrain. Also use caution in steep wind-sheltered terrain, where the recent snow may take a bit of time to bond to an underlying crust.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 20th, 2023 4:00PM
