Conditions are primed for people triggering avalanches. Don't let the lure of deep powder draw you into terrain that's inappropriate for the conditions.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
Unsettled weather and seasonal temperatures for Sunday; a mix of sun and cloud for early next week. SUNDAY: Mainly cloudy with isolated flurries, local accumulations 5-10cm near Whistler with more possible in southern areas. Moderate southeasterly wind and freezing level around 1200m. MONDAY: Sunny with cloudy periods, light northerly wind and freezing level around 1100m. TUESDAY: Sunny with cloudy periods, light northwesterly wind and freezing level around 1200m.
Avalanche Summary
We are still receiving reports of skier (accidental) triggered Size 1 to 1.5 avalanches in the recent storm snow at treeline and higher. Cornices have also been touchy at ridge crests. Avalanche control work with explosives resulted in storm slab and cornice releases to Size 2.5.
Snowpack Summary
Rapid snow and wind loading occurred during the week. The storm snow fell in fluctuating freezing levels, creating storm snow weaknesses. By Friday morning another 15 cm of new snow brought storm snow totals to 70-140cm, which has been redistributed by southerly winds. Early last week we had rain up to 2200m near Whistler, while in other zones like the upper Callaghan it was 35 cm or more of fresh snow. The rain (or snow high in the alpine) started to saturate and load a wide variety of previous surface conditions. Simply put, the upper snowpack is extremely variable with weaknesses within and under the recent storm snow. Of most recent concern is touchy pockets of wind slab that developed Friday on northwesterly features above 2000m.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.