Storm slabs may remain a problem at treeline and above this weekend. Warm temperatures and strong solar effect will add to the risk of loose wet avalanches. Stay alert to changing conditions!
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain on Sunday
Weather Forecast
A weak ridge of high pressure will pass through the region today and tomorrow bringing warmer temperatures and sunny skies, then move on, followed by a cold front that will cross the coast on Sunday. On Monday a high pressure ridge will begin to establish itself to the west of the coast blocking incoming Pacific moisture for the next few days. TODAY: Freezing level rising to around 1700 m, no precipitation expected, winds are forecast to be light southwest. SATURDAY: Cloudy, freezing level around 1800 m, no precipitation expected, winds mostly from the south. SUNDAY: Freezing level lowers briefly to around 1200 m, 15 to 20 cm of snow possible, light southwest winds are forecast. MONDAY: Sunny skies with some cloudy periods, precipitation forecast for the morning, clearing up in the afternoon, freezing level climbing to 1700 m, winds from the south. For more detailed mountain weather information visit: https://avalanche.ca/weather
Avalanche Summary
Reported avalanche activity on Thursday was limited to small storm slabs.
Snowpack Summary
Storm totals in the northern portion of the region are between 10 and 15 cm. Slightly more snow fell in the south of the region where they received 20 to 25 cm of snow. The storm featured moderate south/southwest winds which have likely formed storm slabs at and above treeline. Below the new snow, the snowpack is strong and well-settled throughout with no notable persistent weaknesses. Cornices are huge and fragile.
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.
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.
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.