Regions
Northwest Coastal.
The current storm track has the bulk of the incoming precipitation hitting the South and Central Coast. If the track slides a little further north we could see much more snow and higher avalanche danger.
Confidence
Poor - Track of incoming weather is uncertain for the entire period
Weather Forecast
Synopsis: A steady southwest flow will drive a series of disturbances onto the BC coast this week. There is some uncertainty regarding the track timing of each pulse of heavy precipitation. Currently it looks like Terrace and south will see decent precip amounts, but northern areas may be considerably drier. Tuesday: 5-10 cm. The freezing level is around 500 m. Winds are moderate to strong from the southwest. Wednesday: 5-10 cm. The freezing level is steady around 500 m and winds increase to strong from the southwest. Thursday: Moderate to locally heavy snow. The freezing level should rise to 1000-1200 m.
Avalanche Summary
Several natural size 1-2 wind slabs were observed out of exposed north and east aspects. There was also a report of a remotely triggered size 2 hard wind slab from an exposed NE aspect at treeline. This slide most likely failed on the recently buried surface hoar layer.
Snowpack Summary
Light to locally moderate amounts of new snow now overlie a variety of old surfaces which include: a crust at lower elevations and on solar aspects; old wind slabs in exposed areas, and fairly widespread large surface hoar. Moderate to locally extreme west/southwest winds have redistributed the new snow into soft and hard wind slabs in exposed terrain. I would expect the new snow to be quite reactive, especially where it overlies the surface hoar which was buried on March 9th. This interface is likely to be one to watch as the overlying slab develops.The mid snowpack layers are generally well settled and strong. Facets at the base of the snowpack may resurface as a concern now that spring warming is on the doorstep and full-depth releases are becoming more likely (primarily in the northern part of the region).
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.