Expect forecast new snow to take time to bond to a well established hard crust.
Carefully consider your terrain choices prior to committing to steep avalanche terrain, especially those with evidence of wind transport and loading.
5 to 15 cm of forecasted new snow is expected to overlie a well established melt freeze crust on all aspects, 1600m and below. Above this elevation the new snow will overlie a variety of surfaces including 5-10 cm of preserved snow as well scoured and hard pressed surfaces.
Winds slabs are expected to form and be present on all aspects just below ridgetops and areas that transition into convex features.
The upper snowpack continues to adjust to the recent spring-like weather. As temperatures cool and clouds obscure the sun, expect small loose wet avalanches to continue to only be reactive at lower below tree line elevation terrain.
On Wednesday , field teams reported several loose wet avalanches on south aspect terrain. Explosive avalanche control utilizing a large explosive on a steep north aspect incised rocky gulley feature produced a large (size 2.5) slab avalanche. This avalanche ran on an old melt freeze crust, was 100 cm deep at the crown and ran to the bottom of the run out.
Backcountry users will likely see evidence of a small wet loose avalanche cycle from recent rain and solar input below treeline.
If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.
In terrain above 1600 m up to 10 cm of preserved and wind affected dry snow is likely to exist. An established melt freeze crust can be found at elevations 1600 m and below, expect the new forecast snowfall to take a little time to bond to this old surface. At all elevations the mid and lower snowpack has a number of old melt freeze crusts that are unreactive and overall presents as consolidated, well settled and strong.
Friday Night
Cloudy with flurries, 5 to 10 cm of accumulation. Moderate north winds at ridge top. Treeline temperature -1°C. Freezing levels rise to 1000 m.
Saturday
Cloudy with flurries, 1 to 5 cm of accumulation. Moderate north winds at ridge top. Treeline temperature -1°C. Freezing levels rise to 1000 m.
Sunday
Cloudy with very light flurries a trace to 2 cm of accumulation. Moderate southeast winds at ridge top. Treeline temperature 0°C. Freezing levels rise to 1000 m.
Monday
Mostly clear. No new precipitation. Moderate southeast winds at ridge top. Treeline temperature 0°C. Freezing levels rise to 1200 m.
More details can be found in the Mountain Weather Forecast.
