Avalanche Forecast
Regions: Boundary, East Stikine, Kitimat, Nass, Ningunsaw, Northwest Coastal, Rupert, Seven Sisters, Shames, Stewart, West Stikine.
Seek out sheltered terrain where you can avoid wind slabs.
Confidence
High
Avalanche Summary
Ongoing natural wind slab activity has been reported in the alpine. Skiers on the weekend were able to trigger small wind slabs on lee features at treeline. Please read this report.
Cornices have fallen off east-facing ridges in the alpine. Cornices may have been undermined by the atypical winds.
On Thursday, very large (size 3) slab avalanches were observed near Ningunsaw on south and west-facing slopes. These avalanches may be failing on the deeper weak layer described.
Snowpack Summary
Outflow (north and east) winds have redistributed soft snow into wind slabs in exposed areas. These winds are opposite to regular loading patterns.
In sheltered areas, about 15 cm of snow overlies a layer of buried surface hoar. Otherwise, wind slabs overlie previous hard surfaces or a melt-freeze crust that extends up to about 1700 m.
Near Stewart and Ningunsaw, a poorly-bonded crust about 100 cm deep may act as a weak layer.
Elsewhere, the remainder of the snowpack is reportedly strong with various hard crusts.
Weather Summary
Sunday Night
A few clouds with no new snow, northwest alpine winds 15 to 30 km/h, treeline temperature -18 ºC.
Monday
Partly cloudy with a trace of new snow in the north, northwest alpine winds 20 to 40 km/h, treeline temperature -10 ºC.
Tuesday
Cloudy with 5 cm of new snow, west alpine winds 40 km/h, easing later becoming northeast 20 km/h, treeline temperature -12 ºC.
Wednesday
A few clouds with no new snow, northeast alpine winds 60 to 80 km/h, treeline temperature -12 ºC.
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.
- Seek out sheltered terrain where new snow hasn't been wind-affected.
Avalanche Problems
Wind Slabs
North winds formed wind slabs in exposed areas.
Near Stewart and Ningunsaw, wind slabs could fail on a buried crust, up to 100 cm deep. This is most likely in alpine areas with a shallow snowpack in wind-affected terrain; like south slopes.
Aspects: North East, East, South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2.5