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.
Below Treeline
Below Threshold.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Below Threshold.
Regions
Northwest Coastal.
Invading Arctic air will result in cold and dry conditions. Expect very strong outflow winds in coastal inlets and valleys.
Confidence
Poor - Due to the number of field observations
Weather Forecast
Friday: Mainly sunny but cold. The freezing level is at valley bottom with temperatures around -18 at treeline. Winds are moderate or strong from the E-NE. Saturday: Mainly sunny. Temperature increase with average treeline temps near -10. Winds are moderate from the north. Sunday: Increasing cloud with flurries developing near the coast. Treeline temperatures are around -7. Winds switch to light or moderate from the SW.
Avalanche Summary
A few small explosive triggered wind slab avalanches were reported north of Stewart on Wednesday. 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 into slabs on lee slopes at alpine and treeline elevations. 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.