Dangerous avalanche conditions persist during the heat of the day when the snow surface is moist.
Minimize exposure to avalanche terrain and overhead hazards until cooler weather arrives.
Large persistent slab avalanches continue to be a concern while temperatures remain elevated. Natural activity may begin to slow with cooler temperatures, however, if triggered avalanches will be large and destructive.
Wet loose avalanches remain reactive to human triggering in steep terrain, particularly on solar aspects or where the upper snowpack is moist. Be especially cautious on sun affected slopes near rock outcrops.
On Sunday, natural avalanche activity from prolonged heat continued to be observed, with loose wet, wet slab and persistent slab avalanche activity up to size 3. Steep rocky terrain and direct solar slopes are the most impacted.
We expect natural wet loose and persistent slab avalanche activity to continue until temperatures return to below-freezing.
A melt-freeze crust rapidly deteriorates with daytime heating and solar input to moist or wet snow surfaces at all elevations. The exception is on direct north facing terrain above 2000 m where the surface remains dry.
The top 20 to 50 cm of the snowpack is moist snow. 100 to 250 cm down is a layer of facets overlying a crust. This layer has been the culprit for many recent large avalanches through the extended warm period.
Below the crust, the snowpack is well settled.
Monday Night
Mainly clear skies. 10 km/h southwest ridgetop wind. Treeline temperature +5 °C with freezing levels remaining above 3000 m.
Tuesday
Mainly sunny. 10 to 25 km/h southwest ridgetop wind. Treeline temperature +2 °C with freezing levels falling to 2500 m in the afternoon.
Wednesday
Mainly cloudy. 10 to 25 km/h southeast ridgetop wind. Treeline temperature +1 °C. Freezing levels rise from 1500 m to 2000 m in the afternoon.
Thursday
Cloudy with 1 to 4 cm of snow. 10 to 25 km/h variable ridgetop wind. Treeline temperature 0 °C. Freezing levels rise from 1000 m to 1500 m in the afternoon.
More details can be found in the Mountain Weather Forecast.
