Avalanche danger can rise very quickly with warming and solar radiation. Be aware of changing conditions and overhead hazards. Terrain choices and timing can be critical.
Confidence
Fair - Timing or intensity of solar radiation is uncertain on Saturday
Weather Forecast
Overview: A ridge of high pressure will dominate the coast by Saturday morning bringing mainly sunny skies and rising freezing levels for the forecast period.Saturday: Mostly clear skies / Moderate northerly winds / Freezing level at about 1600mSunday: Clear skies / Light northerly winds / Freezing level at about 1700mMonday: Mostly clear skies with increased cloud late in the day / Light southwest winds / Freezing level rising to about 2600m
Avalanche Summary
Cornices have started to fail with warmer temperatures and sunny skies up to size 2-2.5, without pulling deeper slabs on the slopes below. Numerous loose wet avalanches have occurred up to size 2 on steeper solar aspects.
Snowpack Summary
A melt-freeze crust exists on all aspects up to 2200 m, and dryer snow can be found on high northerly aspects. The recent warmer temperatures have helped to strengthen and settle the upper snowpack, especially on solar aspects. Isolated wind slabs have formed and are sensitive to rider triggers, especially on slopes with a buried crust. Large sagging cornices are looming over slopes and pose a threat, especially when the sun comes out.The early February facet/crust layer is now down close to 200 cm. This layer is largely dormant at this time; however, it should remain on your radar as we transition into a warm-up with minimal overnight refreeze and intense solar output.
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.
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.