Good snow quality at the moment, but watch for fresh wind slabs in the Alpine and take the time to evaluate the early December persistent weak layer before committing to a line.
Weather Forecast
Tuesday will be cloudy with sunny periods and isolated flurries. Temperatures should reach a high of -10 °C. Winds will be westerly at 30-40 km/h. There is no significant precipitation expected over the next several days.
Avalanche Summary
Isolated naturally triggered sluffs up to size 1.0 were observed today in steep Alpine terrain on N, NE and E aspects.
Snowpack Summary
Surface faceting due to cool overnight temps. Recent storm snow is settling and exhibiting very little wind effect in most locations. Wind slabs are evident in some Alpine features, but these seem specific to certain drainages. The Feb 4th Persistent Weak Layer remains the principle concern in the snowpack and is buried up to 65cm at Treeline. Shear tests at this interface persist in the moderate range, but significant variability in the distribution and character of this interface exists through the forecast region.
Problems
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.
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.