The Dec 17 surface hoar layer should still register as a concern in your daily trip plan.
Weather Forecast
We should see a mix of sun and cloud this morning with increasing cloud and flurries late this afternoon. Light SW winds increasing to gusty moderate SW winds should accompany the front as it pushes through. By Friday expect the present surface hoar layer to be buried under 15cm of storm snow, a new layer to watch.
Snowpack Summary
A new surface hoar layer is building right to mountain top. It is widespread to just above treeline and spotty in the alpine. A 2-3cm suncrust can be found on steep solar aspects. The Dec 17 surface hoar layer (down 60-110cm) has a well settled slab sitting on top of it in most locations.
Avalanche Summary
There has been a few solar triggered surface slides observed each day this week at alpine and treeline elevations. Two size 2 slabs occurred on North aspects Tuesday and last weekend a size 2 was ski cut on a moraine feature up Loop Brook. These slabs all came out on the December 17th layer.
Confidence
Intensity of incoming weather systems is uncertain
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.