Wind slabs may be touchy and reactive right now. Choose your objectives conservatively.
Confidence
Moderate - Due to the number and quality of field observations
Weather Forecast
The remnants of a Pacific frontal system will pass through the region later today bringing clouds and very light precipitation overnight and through Monday. No significant precipitation is expected. There should be a bit of a break Monday evening, then a weak system on Tuesday will bring clouds, but very little precipitation is forecast. A ridge of high pressure will rebuild over the province bringing clear skies and no precipitation through the remainder of the week. Freezing levels will rise to 1000 metres during the day, then drop to valley bottom overnight.
Avalanche Summary
Numerous natural, skier controlled and skier accidentals up to size 2 have been reported in the last 2 days on both sides of the divide. Early reports from today speak of a size 1.5 to 2 natural avalanche on a NE aspect at 1900m east of the divide.
Snowpack Summary
New snow and wind Friday night built wind slabs in lee terrain at treeline and in the alpine. A melt freeze crust which formed during the 2nd week of February has been reported 50 to 70cm from the surface in some areas. This crust layer has also been reported with surface hoar in some places, mostly high and north facing. Rain and warm temperatures at lower elevations may have flushed out this weakness in some areas. West of the divide, a layer of buried surface hoar can be found between 70 and 90cm below the surface. Recent reports suggest this layer has become less of a concern. As well the stormy weather has encouraged new cornice growth. These cornices may be huge and unsupported.
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.
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.