Avalanche Forecast

Fair - Timing, track, or intensity of incoming weather system is uncertain

A low pressure system will continue to produce light precipitation on Wednesday.  Unsettled conditions are expected for Thursday and Friday before the next organized system arrives on Saturday. There is currently some weather model disagreement regarding overnight freezing levels.Tues. Night: Precipitation: 8-12mm, freezing level: 500-1000m, ridgetop wind: light S-SWWednesday: Precipitation tapering off midday 2-4mm, freezing level am: 500-1000m pm: 1300m, ridgetop wind: light SWThursday: Mostly cloudy, scattered precipitation 1-3mm, freezing level am: 300-500m pm: 1000m, ridgetop wind: light SW-WFriday: Scattered precipitation 2-5mm, freezing level am: 500-800m pm: 1400m, ridgetop wind: light SW-W

Reports from Monday include isolated natural and human triggered up to size 2.  This includes soft slabs up to 30cm thick and both dry and wet sluffing from steep terrain features.  In the North Columbia region, a size 4 avalanche released on a deep persistent weak layer resulting in the destruction of mature timber and 1 fatality. 

The upper snowpack may have various non-persistent weak layers within the recent storm snow. This includes small surface hoar in sheltered areas, thin sun crusts on solar aspects, rain crusts at lower elevations, and/or small facets. These layers are not widespread and are not expected to persist very long but they continue to produce small slab avalanches. Weak cornices and stubborn wind slabs may also be a concern in some areas.There are three persistent weak layers that remain a concern. The mid-March sun crust/surface hoar layer is down 50-80cm. Recent snowpack tests suggest that the reactivity of this layer is becoming more isolated but many areas still have the potential for human-triggering. The early-March crust/facet/surface hoar layer is down around 80-120cm. Human-triggering has become less likely but the layer still has the potential to produce large avalanches and we continue to see activity stepping down to this layer. The mid-February crust/facet/surface hoar layer is typically down at least 1.5m and direct triggering has become unlikely. However, large triggers like cornices or smaller avalanches can still trigger this layer and produce very large avalanches.