Stay alert to changing conditions with elevation, aspect and time of day due to melt-freeze cycles. Loose wet avalanches or cornice falls may step down to trigger large persistent slabs.
As temperatures rise, large cornice falls will become a concern. They can potentially trigger persistent slabs on the slopes below. Carefully manage your exposure to overhead hazards, during the warmest part of the day.
Surface hoar and facets in the upper snowpack have recently produced large avalanches. These layers are most likely to be reactive at upper elevations where no surface crust has formed.
On Monday, a few wet loose avalanches were seen from steep terrain features. Where a thick, supportive surface crust is found, we expect that triggering avalanches on buried weak layers is unlikely.
Evidence from last week's natural avalanche cycle continued to be reported with very large slab avalanches (to size 4) failing on buried persistent weak layers.
A melt-freeze crust has formed on most surfaces. Dry snow persists on northerly aspects at upper elevations.
Three persistent weak layers remain notable in the snowpack and have been responsible for recent large avalanches. Surface hoar that formed in mid-March can be found 50 to 100 cm below the snow surface. Below this, another layer of surface hoar that formed in early March can be found at a depth of 100 to 150 cm. Additionally, a layer of facets, surface hoar, and/or a crust from mid-February is buried 100 to 200 cm deep.
Wednesday Night
Mainly clear. 20 to 30 km/h north ridgetop wind. Treeline temperature -4 °C. Freezing level 800 m.
Thursday
Mix of sun and cloud. 10 to 20 km/h west ridgetop wind. Treeline temperature +1 °C. Freezing level 1700 m.
Friday
Mix of sun and cloud. 20 to 30 km/h southwest ridgetop wind. Treeline temperature +4 °C. Freezing level 2100 m.
Saturday
Mix of sun and cloud. 40 to 60 km/h south ridgetop wind. Treeline temperature +4 °C. Freezing level 2100 m.
More details can be found in the Mountain Weather Forecast.
