With new snow and warmer temperatures, the snowpack is entering a time of change. Expect buried layers to become more reactive in the coming days.
Weather Forecast
Flurries and freezing rain at lower elevations as the first in a series of coastal fronts arrives this afternoon. Freezing levels spike at 1800m today and then drop off again as a SW flow brings up to 30cm of new snow by Monday. Light SW winds, gusty at times. Here's hoping the forecasted system has the strength to keep the arctic air at bay.
Snowpack Summary
The Dec 15th surface hoar is the main layer of concern. Reports of whumphing, cracking and small slides around tree-line can be attributed to this layer. Slab development has been slow with the past cold, but warming temps and solar input will contribute to slab development over the Dec 15th layer. A thin crust has formed on solar aspects.
Avalanche Summary
No new avalanches were observed yesterday in the highway corridor. A field team on Macdonald West Shoulder was able to ski cut 2 small slabs on the December 15 Surface Hoar Layer in steep, unsupported terrain.
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.