I suspect considerable danger will feel a bit on the high side for areas to the east that are likely to see less snow.
Confidence
Fair - Intensity of incoming weather is uncertain on Saturday
Weather Forecast
By the end of Saturday, western parts of the region could see up to 15 cm of low density new snow as a frontal system tracks along the US/Canadian border. Eastern parts will see more in the region of 5 cm. Moderate southwest winds are expected and alpine temperatures should hover between -5 and -10C. For Sunday and Monday, a series of weak disturbances embedded in a northwesterly flow will bring flurries or very light precipitation. Winds should be generally light or moderate, with the switch from southwesterly to northwesterly expected to occur on Sunday night.
Avalanche Summary
No recent avalanches have been reported from this region. Deep persistent slab avalanches remain possible in isolated terrain features; i.e. heavy triggers in shallow rocky snowpack areas on unsupported slopes. Check out the Avalanche Image Gallery under the Library tab for some photos of last weekends deep persistent slab avalanche cycle.
Snowpack Summary
"Dust on a crust" on southerly aspects, where recent sunshine formed a crust that has since been buried by light snow. Shady slopes do not have this crust. Cool alpine temperatures are promoting facet growth in the upper snowpack keeping the surface snow fairly soft. Just a few cm of recent snow now sits on a variable weak layer comprising surface hoar (most likely in the west of the region), sugary facets on shady N'ly and sun crusts on solar aspects. These interfaces need watching as they receive more snow load and/or wind slab builds on top of these surfaces. Below that, approximately 20 cm of near-surface facets can be found on shady slopes. While the mid-pack is quite strong in most locations, basal facets remain a concern on shady alpine slopes that did not avalanche in the last cycle. Data that supports this lingering concern includes recent professional observations that found easy to moderate compression test results with a sudden "drop" fracture down 80 and 100 cm in a location with a 160 cm snowpack.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.