Avalanche Forecast
Issued: May 3rd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Cornices and Loose Wet.
JMinifie,
Avalanche Canada
Avalanche conditions likely vary with elevation. Wind slabs will likely form in the alpine and loose wet activity is possible at lower elevations.
Summary
Confidence
Moderate - Uncertainty is due to difficult to forecast freezing levels.
Weather Forecast
MONDAY NIGHT: alpine -2C, wind south 30 km/hr, mostly cloudy, 2cm snow
TUESDAY: alpine low -2C high -2C, wind south 30 km/h, cloudy, 10cm new snow in the alpine, possible rain at highway elevation
WEDNESDAY: alpine low -3C high -1C, wind southeast 20 km/h, partly cloudy, freezing levels 1600m
THURSDAY: alpine low -2C high 2C, wind north 15 km/h, mostly cloudy, light precipitation, 2 to 5 cm accumulation, rain possible at highway elevation later in the day
Avalanche Summary
Small (size 1) skier cut wind slab avalanches were reported on Saturday in the high alpine. A size 1.5 wet slab avalanche was reported on Sunday. This slab released from steep, rocky, south facing terrain and ran into lower angle terrain in the valley.
Snowpack Summary
Above 1600 m, around 20 cm of wind pressed dry snow may be found, which overlies a hard melt-freeze crust or other hard surfaces. Below 1600 m, the upper snowpack is wet from recent rain and warm air. The snowpack is isothermal near highway elevations but has still be supporting travel on sleds and skis.
The lower snowpack in White Pass is deep for this time of year with no layers of concern. Areas further inland, such as the Wheaton Valley, may have a shallower and weaker snowpack.
Cornices are still very large. Recent cold temperatures have kept cornice failures to a minimum but they should always be treated with respect in the spring, especially when the air temperature rises.
Terrain and Travel
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Be carefull around freshly wind loaded features.
- Avoid exposure to slopes that have cornices overhead.
- Firm cornices can pull back into flat terrain at ridgetop if they fail.
- Keep in mind that wet avalanches can be destructive due to their high density.
Problems
Wind Slabs
Up to 15cm of new snow and south winds are forecast to arrive in the alpine on Tuesday. This will likely produce sensitive slabs where terrain breaks over steeply at higher elevations. I will once again be approaching these places with caution.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Cornices
Cornices are large at this time of season. Best practice is to stay well-back from them on ridgelines and limit your exposure travelling beneath them.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Assess for the wetness of the snow surface as you travel, particularly as you transition from alpine to treeline elevations later in the day. Use caution in very steep terrain if the snow surface is wet, and limit your overhead exposure of steep slopes.
Aspects: All aspects.
Elevations: Treeline.
Likelihood
Expected Size
Valid until: May 5th, 2021 4:00PM
