Watch for reactive storm slabs to form as the new snow settles. Tricky conditions still exist due to a touchy buried weak layer. Conservative terrain selection is critical.
Weather Forecast
SATURDAY: Up to 13cm snow overnight, with another 5cm possible thought he day, rain expected at lower elevations, moderate to strong westerly winds, freezing level of 1300m. SUNDAY: sunny with cloudy periods, light westerly winds, 1300m freezing level. MONDAY: sunny with cloudy periods, light westerly winds, freezing level around 2500m, +5C at 2000m.
Avalanche Summary
The recent storm snow is becoming increasingly reactive with numerous small natural and skier controlled avalanches reported in the last two days. Although there haven't been any persistent slab avalanche reported recently I think it could still be possible to trigger large destructive avalanches in isolated open, unsupported terrain features at and below treeline.
Snowpack Summary
Up to 30cm of new storm snow is settling to form a widespread soft slab. Moderate southwesterly winds on Thursday formed fresh wind slabs in lee features at treeline and in the alpine. Bellow 1900m a crust may be found about 50cm below the surface although this layer seems to be most prevalent in the Monashees. In the far south of the region a layer of surface buried at the end of January may be found at around this depth in isolated features at treeline and in the alpine. Deeper in the snow pack, the surface hoar layer from early January is now down 80-120cm in most places. Although this layer has become harder to trigger and is variably reactive in recent snowpack tests, it still has the potential to produce large avalanches. I would continue to show respect for this layer especially in steep, open terrain at treeline and below through the weekend.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.