The weakness in the upper snowpack remains a concern for skier triggering with potentially wide propagations. The incoming storm forecasted for tomorrow is expected to overload this tricky layer. Cornices are growing larger with strong winds.
Weather Forecast
A ridge will remain over the region today, keeping things fairly dry. Later today a frontal system will slide into the region bringing increased cloud and flurries. Winds will be light to moderate from the W-SW. On Friday a stronger front will push through, with forecasted snowfall amounts of 25-35 cm and strong westerly winds.
Snowpack Summary
Hard and Soft slabs overly a weak layer of surface hoar, buried 50-60cm. This surface hoar is wide spread, and is best preserved and reactive between 17-1900m, and is most reactive on solar aspects where it rests on a buried sun crust.
Avalanche Summary
Few natural avalanches have been observed in the backcountry. Avalanche control yesterday produced a few avalanches to size 2.5. While avalanche activity has tapered off lately, test results in profiles consistently produce easy fast shears (RB2 Whole Block) done 50 cm on the Feb. 12 surface hoar PWL. This PWL can be found almost everywhere.
Confidence
Intensity of incoming weather systems is uncertain on Friday
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.