Watch for an increasing avalanche danger this weekend with forecast freezing levels rising above mountain top.
Weather Forecast
Mainly cloudy today with light winds and an alpine high of -4C. The freezing level should rise to 1200m later today and is forecast to rise to 2900m for the weekend with an alpine high up to +5C forecast for Sunday. Watch for an increasing avalanche danger.
Snowpack Summary
Nearly 50cm of snow has fallen in the past 5 days. On southerly aspects, NE winds yesterday will have reverse loaded lees creating deeper pockets of soft slab. In exposed alpine areas and a ridge crest it will have buried old windslabs. The Jan 2 freezing rain crust is down ~90cm. The Nov 21st interface is now 1-2m in deep
Avalanche Summary
Yesterday skier remote triggered size 1 avalanche at 2100m on Puff Daddy from 10m distance, skier triggered slide in the Christmas Trees size 1, skier remote triggered size 1 slide 1700m up NRC. 20 avalanches observed in the highway corridor mostly in the size 2-2.5 range. Wed, skier accidental size 3.5 from the top of Camp West avalanche path.
Confidence
Freezing levels are uncertain
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.