Yesterday's avalanche accident near Lions Bay highlights that it's still winter at higher elevations.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
MONDAY: Overcast sky with another 10 or 15 cm of snow at high elevations overnight Sunday and into Monday morning. Alpine and Treeline temperatures from a couple of degrees below freezing to a couple of degress above freezing. Freezing level around 900 m. Light to Moderate southerly windsTUESDAY: Mix of sun & cloud with a trace of precipitation. Termperatures at Treeline between -3 and +3 C with freezing level near 1500m. Light southeast or east winds.WEDNESDAY: Overcast with around 15 cm of snow at higher elevations but rain down lower. Similar temperatures (as cold as -5C and as warm as +2C) and freezing level (around 1600m). Moderate SE wind.
Avalanche Summary
On Monday the main concern is wind slab avalanches where the recent precipitation fell as snow and was drifted by the wind behind ridges. At tree line expect small loose wet avalanches in steep terrain. Saturday's fatal avalanche on Mt Harvey (near Lion's Bay) was the result of people being on a cornice that broke.
Snowpack Summary
Saturday's cold stormy weather brought snow to the mountains as low as 800m. It's still winter up high! Sunday was a calmer and dryer day but isolated lingering wind slabs remain a concern. At lower elevations, rain has saturated an already wet snowpack.
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.
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.