We're starting to transition to a spring snowpack. Solar and daytime heating will increase avalanche hazard. Avoid South and West aspects when the effects of the sun are strong!
Weather Forecast
A low pressure system moving inland from the coast today will displace the ridge of high pressure currently sitting over the Southeastern BC. This morning will remain clear with cloud building in the afternoon and potential for convective flurries. Winds will be in the 10 -30km/hr range from the S and freezing level will go up to 1600m.
Snowpack Summary
South winds and 20-30 cm of snow in the last 24 hrs have built variable soft slabs in the alpine and exposed treeline areas. Below 1900m, 20-30cm sits on a supportive crust, this new snow became moist in the afternoon yesterday and was reactive. Persistent layers exists down 150cm (February crust) and near the base of the snowpack (November crust).
Avalanche Summary
We experienced a natural avalanche cycle in the park yesterday to size 3. These were triggered by rapid loading from convective flurries, steady winds and warm temps. Field teams in the Asulkan area found a moist slab below 1900m. This slab was touchy where it was sitting on a crust and produced loose wet avalanches to sz 2 with heavy debris.
Confidence
Timing or intensity of solar radiation is uncertain
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.