Warm wet new snow and rain overnight, and warming temperatures have combined to create increasing avalanche danger.
Weather Forecast
A low pressure system sits over the Selkirk mountains, bringing warm temperatures and locally moderate to heavy precipitation. Winds will be moderate from the SW. Freezing levels will be around 2000m today.
Snowpack Summary
Moist snow and rain overnight with snow sticking to the trees at about 1600m elevation this morning. Heavy wet new snow over an isothermal snowpack has been reported from a treeline observatory, and avalanche activity can be expected today.
Avalanche Summary
A few natural avalanches were reported yesterday, from size 2-3. Many recent glide crack avalanches.Numerous loose wet avalanches to size 3.0 in the backcountry on solar aspects over the last week.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
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.
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.