A surface hoar layer is buried by 40cm of settling snow and could become increasingly reactive. Take the time to evaluate the snowpack as you transition into avalanche terrain, pay attention to cracking and settlements in your surrounding area.
Weather Forecast
A ridge of high pressure will build throughout the day bringing sun but no snow. The winds will be from the North in the15-40km/hr range with an Alpine high of -17... bbrrr thats cold!! The clear skies and cold temps will continue over the weekend and into early next week. No snow in the forecast.
Snowpack Summary
50cm of settling snow sits on the Dec 15 surface hoar, persistent weak layer. On steeper solar aspects this layer is a crust and/or a crust with small surface hoar on top. The crust runs up into the alpine on steep south and west aspects. Deeper in the snowpack there are a series of crust layers that are currently bonding well.
Avalanche Summary
Numerous natural avalanches over the past few days up to sz 2.5 from steep terrain. The surface hoar layer at tree line and below will become increasingly reactive as the storm snow settles into more of a cohesive slab. Be aware of this when traveling in steeper, open areas or where a slab exists.
Confidence
Due to the number of field observations
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.