Avoid avalanche terrain.
Unseasonably warm weather will likely result in a widespread natural avalanche cycle.
The likelihood of persistent slab avalanches will increase with each day of warm weather. Uncertainty remains about how the persistent weak layer will react to the rapid warming.
Intense warming will likely trigger numerous loose wet avalanches. These may step down to deeper layers resulting in larger-than-expected avalanches.
On Tuesday, large persistent slab and wind slab avalanches (up to size 2.5) occurred naturally on east slopes at treeline and alpine, respectively. Whumpfs and shooting cracks were also observed at treeline and below. Over the last week, skiers were surprised by large avalanches; several were remotely triggered from a distance from low-angle or flat terrain.
Expect increasing natural avalanche activity with the incoming warm weather.
Expect surface snow to be wet or moist.
A layer of weak, faceted crystals over a crust, or surface hoar, is the primary layer of concern, buried around 40 to 80 cm deep. This layer has been reactive, especially at treeline and below, over the last week.
Friday Night
Mostly clear. 10 to 20 km/h southwest ridgetop wind. Treeline temperatures around 0 °C. Freezing level 3000 m.
Saturday
Sunny. 15 to 30 km/h southwest ridgetop wind. Treeline temperatures around +8 °C. Freezing level rising to 3200 m.
Sunday
A mix of sun and clouds. 40 to 50 km/h southwest ridgetop wind. Treeline temperatures around +6 °C. Freezing level 2500 m.
Monday
Partly cloudy. 15 to 20 km/h southwest ridgetop wind. Treeline temperatures around +4 °C. Freezing level 2000 m.
For more details, see the Mountain Weather Forecast.
More details can be found in the Mountain Weather Forecast.
