Regions
Northwest Inland.
New snowfall amounts are expected to vary greatly across the region. Pay close attention to how much new snow fell in your riding area as this will affect your local Avalanche Danger.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Friday
Weather Forecast
On Saturday expect a mix of sun and cloud, light flurries and moderate/variable winds. On Sunday the region may see an additional 3-8cm of new snow and moderate easterly winds. On Monday, expect a mix of sun and cloud with light winds. Freezing levels should hover around 1300m for the forecast period.
Avalanche Summary
On Wednesday, a size 3 deep persistent slab avalanche was accidentally triggered by a skier in alpine terrain in the north of the region. To our knowledge, nobody was injured in the incident. The slab, which ran on basal facets, was up to 200cm deep, 200m wide and 500m long. There have been a handful of recent similar avalanches triggered on basal facets in the mountains north of Kispiox. Although observations have been limited, I suspect new snow and wind on Wednesday, Thursday and Friday also promoted a round of wind slab activity at treeline and in the alpine.
Snowpack Summary
On Thursday and Thursday night, 3-15cm of new snow fell with the highest accumulations occurring in the southwest of the region. Strong winds shifted the new snow into new wind slabs at treeline and in the alpine adding to an ongoing wind slab problem. A layer of surface hoar from early January can be found in isolated locations between 60 and 140cm down. There hasn't been any activity reported on this layer for a couple of weeks now and it is becoming less of a concern. In shallower areas the snowpack sits on a weak base layer of facetted snow. Recently, this layer has been active in the north of the region, responsible for several large avalanches in unsupported alpine terrain.
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.