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 are becoming a concern. They can potentially trigger persistent slab avalanches on the slopes below. Carefully manage your exposure to overhead hazards, during the warmest part of the day.
Several weak layers persist in the snowpack. These layers are most likely to be reactive at upper elevations where no surface crust has formed. Human-trigger remains possible on thin or variable snowpack.
Wet loose avalanches were reported up to size 1.5 from steep sunny slopes at all elevation. On Sunday, warm temperatures and sunshine triggered a few natural cornice falls, pulling slabs on the slopes below up to size 2.5. Evidence of large avalanches from last week continues to be reported. Many failed on the buried persistent weak layers.
Where a thick, supportive surface crust is found, we expect that triggering avalanches on buried weak layers is unlikely.
Variable wind affect and wind slab covers open terrain at upper elevations. A crust is found up to 1500 m and higher on solar slopes. New surface hoar up to 10 mm has formed on treeline and alpine features sheltered from the sun and wind.
Three layers of concern currently exist in the upper-mid snowpack. Surface hoar and a crust that formed in mid-March can be found 30 to 70 cm below the snow surface. Below this, another layer of surface hoar that formed in early March can be found at a depth of 60 to 100 cm. Additionally, a layer of facets, surface hoar, and/or a crust from mid-February is buried 120 to 200 cm deep.
The remainder of the snowpack is well consolidated, and there are no current concerns.
Wednesday Night
Mainly clear. 20 to 30 km/h northwest ridgetop wind. Treeline temperature -3 °C. Freezing level returning to valley bottom.
Thursday
Mainly sunny. 10 to 20 km/h southwest ridgetop wind. Treeline temperature +1 °C. Freezing level 1800 m.
Friday
Mix of sun and clouds. 20 to 30 km/h southwest ridgetop wind. Treeline temperature + 2 °C. Freezing level 2000 m.
Saturday
Mix of sun and clouds. 30 to 50 km/h southwest ridgetop wind. Treeline temperature + 4°C. Freezing level 2200 m.
More details can be found in the Mountain Weather Forecast.
