The next big change is on Sunday: Sunny, warm weather will be driving avalanche problems.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain on Sunday
Weather Forecast
The clouds will clear out Saturday evening, giving way to pleasant weather on Easter Sunday. Back to wet spring weather on Monday.SUNDAY: Sunshine in the morning, clouding over in the afternoon. Freezing level rising to 1800 m, highs near +3. Winds light southerly.MONDAY: Rain (5-10mm) up to 1600m, with wet snow higher up. Winds 20-30 km/h from the south.TUESDAY: Wet snow or rain. Freezing level around 1500 m. Winds moderate southwesterly.
Avalanche Summary
On Thursday, explosives control work was able to trigger a Size 2 storm slab on a northwest facing aspect in the alpine near Whistler. Skiers were also able to trigger several Size 1 soft slabs in steep leeward alpine terrain. Expect avalanche activity to increase with the warm weather on Sunday.
Snowpack Summary
We've had 20-30 cm of settling storm snow above 1500m. Winds were moderate to strong from a variety of directions and have created fresh wind slabs in exposed terrain at treeline and above. On Sunday the sun will come out in full force - it's a good time to remember that cornices remain large in some areas and could trigger large avalanches when they fail (especially when warmed by the sun). The fatal accident near Lions Bay a week ago illustrates the danger of cornices breaking off, and the large avalanches they can trigger.
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.
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.
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.