Avalanche Forecast
Issued: Mar 11th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
wlewis,
Avalanche Canada
It's not time to step out yet, resist the temptation of large, open terrain.
Storm snow is reactive to human triggers and buried weak layers remain capable of producing very large avalanches.
Summary
Confidence
Avalanche Summary
Small slabs were reactive to rider traffic on Sunday within the storm snow, sitting over facets and surface hoar.
No persistent slab activity has been reported since Thursday, however, avalanches within the last week have been large and destructive, running full path. The photos below show an explosive triggered avalanche near Nelson, and a rider triggered avalanche in the Bonningtons, both several days old.
Snowpack Summary
Storm totals are expected to reach 30-40 cm by Tuesday afternoon. Storms slabs are currently not bonding well with the old snow surface - a crust on sun affected slopes, surface hoar in sheltered terrain, and wind affected snow in exposed areas.
A widespread crust with weak facets above is buried 100-150 cm deep and remains a very concerning layer for human triggering. While reports suggest this layer is becoming harder to trigger, it has produced very large avalanche activity this week.
The snowpack below the crust is generally strong.
Weather Summary
Monday Night
Cloudy with up to 15 cm of snow overnight in the Selkirks, and 5 cm in the Purcells. 30-40 km/h southwest ridgetop wind. Freezing levels remain above 1000 m.
Tuesday
Cloudy with another 10 cm of snow for the Selkirks and flurries for the Purcells. 30-40 km/h southwest ridgetop wind. Freezing levels rise to 1500 m, with treeline temperatures around -3 °C.
Wednesday
Mostly clear skies. 10 km/h northwest ridgetop wind. Freezing levels rise to 1800 m, with treeline temperatures around -1 °C.
Thursday
Clear skies. 20-40 km/h northwest ridgetop wind. Freezing levels spike to 2000 m, with treeline temperatures around +1 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be careful to keep storm day fever from luring you out into bigger terrain features.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Problems
Persistent Slabs
While uncertainty exists about the likelihood of triggering, storm snow will add load and may increase reactivity. Avoid areas where the snowpack thins, like steep, rocky start zones where weak layers are more easily triggered.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
Storm snow is likely not bonding well with the snow below producing small but reactive slabs. Small avalanches could step down to deeper weak layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 12th, 2024 4:00PM
