Avalanche Forecast
Issued: May 1st, 2021 2:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Cornices and Loose Wet.
mconlan,
Avalanche Canada
Avalanche conditions likely vary with elevation. Wind slabs may linger in the alpine and loose wet activity is possible at lower elevations.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
SATURDAY NIGHT: alpine -4C, wind south 10 km/hr, mostly cloudy, trace precipitation
SUNDAY: alpine low -5C high -2C, wind south 15 km/h, mix of sun and cloud, trace precipitation
MONDAY: alpine low -3C high -1C, wind southeast 15 km/h, mostly cloudy, light precipitation, 1 to 3 cm accumulation
TUESDAY: alpine low -3C high -1C, wind south 30 km/h, mostly cloudy, light precipition, 2 to 5 cm accumulation
Avalanche Summary
Large (size 2) wet loose avalanches have been observed throughout the region, particularly during periods of rain or with warm air temperature.
Snowpack Summary
Above 1400 m, around 20 cm of dry snow may be found, which overlies a hard melt-freeze crust or other hard surfaces. Below 1400 m, the upper snowpack is wet from recent rain and warm air. The snowpack is isothermal near highway elevations, meaning it is generally unsupportive to human traffic.
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
- Carefully evaluate steep lines for wind slabs.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
- Avoid terrain traps where the consequence of any avalanche could be serious.
Problems
Wind Slabs
20 cm or more of dry snow may be found above around 1400 m. Recent strong southwest wind may have blown this snow into wind slabs in lee terrain features. Assess for slab properties before committing to steep wind-loaded alpine terrain.
Aspects: North, North East, East, South 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 treeline to alpine elevations. 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 3rd, 2021 4:00PM
