A spring diurnal pattern dominates. Avalanche danger will be lowest during overnight cool conditions and may increase during the heat of the day.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
WEDNESDAY NIGHT: Clear skies, 20 km/h northeast wind, alpine temperature -6 C.
THURSDAY: Clear skies, 20 km/h northeast wind, alpine temperature -4 C, freezing level 1000 m.
FRIDAY: Mix of sun and cloud, 20 km/h northeast wind, alpine temperature -4 C, freezing level 1100 m.
SATURDAY: Mix of sun and cloud, 20 km/h northeast wind, alpine temperature -3 C freezing level 1200 m.
Avalanche Summary
There is widespread evidence of avalanche activity from the warm air temperature last weekend, including large loose wet avalanches and wet slab avalanches. Check out this MIN for a few photos.
Snowpack Summary
A dusting of snow overlies a hard melt-freeze crust to the mountain tops from recent warm air and sunny skies. The snow may moisten during the heat of the day, particularly on sun-exposed slopes and on all aspects below the freezing level.
The White Pass area has a deep snowpack without any layers of concern. A thinner and weaker snowpack exists in inland regions, such as the Wheaton Valley.
Terrain and Travel
- Avoid travelling on slopes below cornices.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Cornices
Cornices are large and will weaken with daytime warming. Stay well back from them on ridges and avoid travelling beneath them. A cornice fall has the potential of triggering slab avalanches on the slopes below.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Wet loose avalanches are possible on sun-exposed slopes during the heat of the day, particularly during sunny conditions. Avalanches are not expected during overnight periods when cooling is expected.
Aspects: East, South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 23rd, 2021 4:00PM
