Travel is safer early in the day. Expect crusts to break down quickly with daytime warming and solar input, leading to dangerous avalanche conditions on all aspects.
Weather Forecast
Full sun today with freezing levels rising to 2100m. Ridge winds vary from light to moderate from the NW. Clear skies and cooler temps may promote a refreeze of the snowpack tonight with freezing levels dropping to 1400m. Warm daytime temperatures will persist into next week. The high pressure ridge will break down on Tuesday bringing light rain.
Snowpack Summary
Daytime warming turned the recent storm snow into a 30cm moist layer. There was no full refreeze last night, but under clear skies a weak surface crust likely formed. Below the crust the upper ~70cm of snow is warm, moist and weak. Extreme southerly winds have likely spoiled any remaining north facing powder stashes leaving touchy wind slabs.
Avalanche Summary
Several loose wet avalanches were observed in the highway corridor up to size 2.5. Some time yesterday evening, a large mid-elevation glide crack released on Mt MacDonald creating a large size 3 avalanche.
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.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.
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.