Confidence
Fair - Due to the number of field observations
Weather Forecast
Arctic air will slowly dissipate and alpine temperatures are forecast to climb towards -10 by Tuesday. Freezing level will remain at valley bottom. A Pacific frontal system is forecast to arrive on the coast Wed. or Thurs. and move into the interior bringing milder temperatures and precipitation. Timing and amount of moisture is uncertain.
Avalanche Summary
No reports of recent avalanche activity. Wind slabs on lee slopes are the major concern at this time.
Snowpack Summary
Snowpack depths vary greatly across the south coast inland area. Reports from the Cascades show 160cm @ 2000 metres, but the Duffey lake has only 54 cm at 1890 m.Arctic outflow N winds continue to scour north slopes and deposit wind slabs on S-SW slopes at tree line and above . Surface hoar is growing in protected locations near tree line and reports on Friday indicate the storm snow is faceting down to 30 cm from the surface.Terrain below tree line is mostly below threshold for avalanche activity and solid. A few crusts with faceting may be found near the base of the snowpack, especially at higher higher elevations. No observations of avalanches on these crust/facet layers have been reported up to this time, but they are worth keeping an eye on.
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.