Buried surface hoar from mid December continues to be a concern in parts of the region. Dig down to identify if this is a concern in your area.
Weather Forecast
Overcast with freezing levels at valley bottoms for the duration of the forecast. Light south or southeast winds and alpine temperatures around -7 during the days. Some flurries or light snow falls with little accumulation expected. The south of the region may see a bit more snow, but probably total snowfall of 5-10 cm.
Avalanche Summary
Some loose snow avalanches continue to be reported from steep alpine terrain. Last week several large avalanches were skier triggered in the southern Purcells, west of Kimberly, on buried surface hoar. Something to keep in mind when looking for new lines!
Snowpack Summary
Conditions are quite variable throughout the region. In the southern Purcells, (west of Kimberley), a prominent layer of buried surface hoar has shown to be reactive to human triggers. In this part of the region, it's buried down 40 cm with a cohesive slab above it. Further north, this surface hoar layer is 60-120 cm down and has been sporadically reactive to skiers, most recently on north-west facing alpine slopes near Golden. At alpine elevations, this interface exists as a surface hoar/facet layer sitting on a crust. The lower snowpack is generally considered to be well settled. Solar aspects may now have sun crust from the recent warm temperatures. New and old wind slabs may be found in the lee of ridges and ribs on a variety of slopes, and surface hoar is forming in protected cool areas.
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.
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.