The recent storm snow is likely still reactive to human triggering, especially in wind-loaded terrain at higher elevations.
Check out our recent post-storm conditions video.
Multiple weak layers buried up to 2.5 m have produced very large avalanches recently. While the likelihood of triggering these layers is now pretty low, they still deserve respect until we have more post-storm information.
The recent storm snow is expected to remain reactive to triggering at high elevations where a crust is not present on the surface. This storm snow will be most reactive in wind loaded areas.
The recent atmospheric river weather event resulted in a widespread avalanche cycle which ended on Friday. Avalanches occurred on all aspects and elevations, and were a mix of slab and loose, wet and dry. Avalanches up to size 4 were observed and many were running full path to valley bottom.
While natural avalanche activity has now tapered off, it may still be possible to trigger avalanches, especially above the rainline where the snow surface remained dry.
A widespread melt-freeze crust is expected to have formed near the snow surface everywhere except the high alpine. At the highest elevations, over 1 m of storm snow has accumulated over the past week. At lower elevations, substantial rainfall had saturated the upper snowpack at and below treeline.
A thick crust buried earlier in March can be found down 70 to 120 cm at treeline and below.
Three weak layers of surface hoar, facets and/or crust that formed in January and February are found down 100 to 250 cm. With a new crust capping the snowpack, it is expected that these layers are becoming a lot less likely to result in avalanches, but caution is still needed until we have more post-storm data.
Saturday Night
Partly cloudy. 1 to 2 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -7 °C.
Sunday
Mostly cloudy. 1 to 2 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -9 °C.
Monday
Mix of sun and clouds. 1 to 2 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Tuesday
Mostly cloudy. 10 to 20 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -4 °C.
More details can be found in the Mountain Weather Forecast.
