Change is in the air, but even short periods of sunshine combined with high freezing levels can pack a punch. Loose wet avalanches are possible on sun-exposed slopes in the afternoon.
Steer clear of cornices from above and below.
Summary
Confidence
Weather Forecast
Overnight Thursday: Clear with a light wind. Alpine temperatures near -2 and freezing levels 800 m.
Friday: A mix of sun and cloud. Ridgetop wind light to moderate from the southwest. Alpine temperatures near -1 (Duffy) and +6 (Coquihalla) and freezing levels 2000 m.
Saturday: Precipitation 10-20 mm falling as snow in the alpine and rain below. Ridgetop wind moderate from the northeast. Alpine temperatures near -2 and freezing levels 1700 m.
Sunday: Snow 5-10 cm. Ridgetop wind strong from the southwest. Alpine temperatures near -2 and freezing levels 1700 m.
Avalanche Summary
Over the past week natural and explosive triggered wet slab avalanches were reported mostly from large solar slopes and running to valley bottom up to size 3.5. An ongoing natural cycle of wet loose avalanches up to size 2 has been the theme.
Natural avalanche activity may taper Friday with slightly cooler temperatures and some cloud cover but keep these avalanche problems in mind if the sun is shining in your local riding area, especially in the afternoon.
Snowpack Summary
A melt-freeze crust exists to the mountain top on solar slopes and up to 2000 m on polar slopes. Above 2000 m on North facing terrain, you may find dry snow and a generally well-settled snowpack. Below treeline elevations, the snowpack has been isothermal and will likely form a crust as freezing levels drop.
Cornices are large and looming along ridgelines. They are weak and very unpredictable.
Terrain and Travel
- Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
- Keep in mind that wet avalanches can be destructive due to their high density.
Problems
Loose Wet
Wet loose avalanche activity is possible on sun-exposed slopes in the afternoon only if the surface crust softens and weakens. These avalanches are generally smaller than wet slabs but they can gather mass as they travel and reach low elevations.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are at their largest at this time of year, and become weaker with warm temperatures and solar radiation.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 23rd, 2021 4:00PM
