Increased reactivity of the Jan 17 surface hoar/crust layer is due to recent loading of storm snow. Distribution is spotty, so dig down to verify if this layer is present in your local area.
Weather Forecast
Thankfully, today is forecasted to be the coldest day. Temperatures will climb back to a somewhat reasonable level by tomorrow to about the -18 range in the valley. A clearing trend will ensue, and the wind will drop back to light from the West. No snow is forecasted for a while.
Snowpack Summary
30-45cm of recent storm snow is being redistributed into windslabs above treeline. In locations up to 2200m a thin but reactive layer of surface hoar (Jan 17) and/or crust is found down 60-70cm. The mid and lower snowpack have few weaknesses, however concern remains for the weak facets below the Dec 10 interface in shallow areas.
Avalanche Summary
No avalanches reported or observed today, however yesterday there were two skier accidental avalanches size 1.5. One was on Vermillion Peak (reported on the MIN) the other was at Bow Summit. Both were suspected to have slid on the Jan 17 Surface Hoar. No injuries or lost gear in either slide.
Confidence
Due to the number of field observations on Sunday
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.