Avalanche Forecast
Regions: Tutshi, Wheaton, White Pass East, White Pass West, Yukon.
Cold smoke awaits.... get at it before the wind does! Once the wind picks up, back off of exposed terrain features and head to more sheltered zones. Be mindful that deeper instabilities still exist and have produced large recent avalanches.
Confidence
Moderate
Avalanche Summary
Wind slabs have been reactive lately and are expected to continue. Natural wind slab avalanches up to size 2 and wind-triggered loose dry up to size 1.5 were reported in the White Pass area on Tuesday. On Monday, a size 1.5 skier-triggered wind slab was reported in this MIN from Fraser. We really appreciate you for sharing!
Our field team recently observed a large natural wind slab avalanche that stepped down to a deeper weak layer in the Paddy Peak area, likely during the outflow winds on the weekend.
Snowpack Summary
30-40 cm of recent low density storm snow sits over firm, old, wind-hammered surfaces. If the wind picks up on Thursday, all this fresh snow is available to blow around and wind slabs are likely to form in lee terrain features.
In the mid snowpack, a couple of buried crusts have been associated with overlying surface hoar on north to east aspects as high as 1700 m, buried around 50 and 90 cm deep. Recent large avalanches are suspected to have run on the deeper of the two layers.
Weather Summary
Wednesday night
5-10 cm of new snow. Moderate southwest wind. Alpine low -12 ºC.
Thursday
Cloudy with isolated flurries. Moderate southwest wind. Alpine high -10 ºC.
Friday
A mix of sun and cloud with isolated flurries. Light variable wind. Alpine high -15 ºC.
Saturday
A mix of sun. Light to moderate easterly wind. Alpine high -18 ºC.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- The best and safest riding will be on slopes that have soft snow without any slab properties.
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Wind slabs are most reactive during their formation.
- Recent new snow may be hiding windslabs that were easily visible before the snow fell.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
Avalanche Problems
Loose Dry
Low density snow that hasn't formed a slab can be prone to sluffing in steep terrain. Sluff can be fun as long as it's managed appropriately in order to avoid getting pushed off your feet or into terrain traps.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 1.5
Wind Slabs
Watch for fresh wind slabs forming in lee terrain features if the wind picks up on Thursday!
Aspects: North, North East, East, South East, South, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 1.5
Persistent Slabs
A weak layer of surface hoar and/or facets buried ~100 cm deep has produced occasional large, widely propagating avalanches on north to east aspects above 1500 m. Some have been remotely triggered from hundreds of meters away! A layer at this depth may not show obvious signs of instability. Best to avoid steep or unsupported high consequence alpine terrain.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood: Unlikely
Expected Size: 2 - 3