Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Below Threshold.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Below Threshold.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Below Threshold.
Regions
Northwest Coastal.
Cold, dry, and windy conditions persist under an Arctic ridge of high pressure.
Confidence
Fair - Due to the number of field observations
Weather Forecast
A push of Arctic air from the north is bringing dry, cold and windy conditions to the northwest. Valley bottom temperatures will hover around -10 to -15. We should continue to see moderate or strong outflow winds (from the E-NE) in coastal valleys and inlets. On Sunday we could see increasing cloud and light snowfall as a system moves in from the northwest. This could also increase temperatures by a few degrees, but it will remain cool.
Avalanche Summary
A few small explosive triggered wind slab avalanches were reported north of Stewart this week. These slides were from northerly aspects near treeline and were up to 40 cm deep. We have had no reports from popular recreational spots in the region. Let us know what you are seeing at [email protected].
Snowpack Summary
As we begin our forecasting season, we are working with limited information from the field. Early reports suggest there's enough snow for avalanches at alpine and some treeline elevations. Recent snow has likely been redistributed by gusty and variable winds forming dense or hard wind slabs on lee slopes and stripping windward slopes bare. This snow may overlie a weak old snow surface (surface hoar, facets and/or a crust) which developed during November's dry spell. Check the bond of the snowpack at this level and take a cautious approach as new snow builds deeper above this layer.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.