Avalanche Forecast
Issued: May 4th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet and Deep Persistent Slabs.
CB,
Avalanche Canada
Natural avalanches are still possible, limit time in avalanche path runouts on all aspects.
With no overnight refreeze for a week, the upper snowpack is very soft, making for difficult travel and hazardous riding conditions.
Summary
Confidence
High
Avalanche Summary
Avalanche control today has produced isolated sz 4 and numerous sz 2-3 avalanches. This is capping off a very active week of spring avalanche activity. Which had wet/loose natural and controlled avalanches with numerous sz 3, and isolated sz 4's. Many avalanche paths failed down to ground once the avalanches reached Treeline elevations and lower.
Snowpack Summary
Warm temps have penetrated the snowpack creating an moist, isothermal snowpack treeline and below on all aspects and into the alpine on solar aspects. Buried crusts in the upper 50 cm are breaking down. Shallow snowpack features have loose, weak snow to ground.
20-40cm above the ground the Nov 17 basal weakness can still be found in many areas.
Weather Summary
Warm and dry weather will come to an end on Fri, as a trough of low pressure brings light precip and dropping freezing levels.
Tonight: Clear, Alpine Low 8°C, FZL 3200m, mod E ridgetop wind
Fri: Sunny w/cloudy periods, Alp High 12°C, FZL 3500m, mod, gusting to strong E winds
Sat: Cloudy w/sunny periods + iso wet flurries, Alp high 6°C, FZL 2800m, mod S winds
Terrain and Travel Advice
- Minimize exposure to overhead avalanche terrain, large avalanches may reach the end of runout zones.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Loose Wet
With intense solar radiation and no overnight refreeze, the snowpack is moist and weak. Wet loose avalanches could be triggered in steep terrain. We have observed these loose avalanches stepping down to the basal weakness at Treeline elevations and lower.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Several hot days with no overnight refreeze has warmed and destabilized the snowpack. This early season basal weakness has woken up below 2000m and is producing very destructive avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: May 5th, 2023 4:00PM
