New snow will be especially sensitive to seeing the sun for the first time. Below, a complex upper snowpack contains suspect layers at prime depth for human triggering.
A widespread weak layer of surface hoar/crust/facets is buried around 30 to 50 cm deep. Avalanche activity has tapered recently but the snowpack structure remains a concern as new snow load is added.
New snow sits over large surface hoar crystals, making for a poor bond. In wind-loaded terrain where it is deep enough for slabs to form, they will be touchy. An underlying crust makes for a slippery bed surface for avalanches to run on.
Up until early last week, small human-triggered persistent slab avalanches were being reported regularly on the late January surface hoar/crust/facet layer. On Thursday, a skier-controlled cornice failure did not trigger the layer on the slope below.
Looking forward, this layer may become active again as it is loaded with new snow.
10 to 15 cm of new snow sits over a widespread layer of large surface hoar crystals, and/or a crust on solar aspects. This is the uppermost of three major surface hoar/crust layers in the upper snowpack.
At this time, the most concerning of them is the deepest and most widespread. Buried in late January, it now sits roughly 40 to 60 cm deep. It is composed of surface hoar on a melt-freeze crust, with a thick layer of facets below. Avalanche activity on this layer has tapered but this snowpack structure remains a concern as new snow load is added.
The mid and lower snowpack remain well settled, with no other significant concerns at this time.
Saturday Night
Partly cloudy. 1 cm of snow. 20 km/h west ridgetop wind. Treeline temperature -7 °C.
Sunday
Mostly sunny. 20 km/h west ridgetop wind. Treeline temperature -7 °C.
Monday
Mostly cloudy. 10 to 15 cm of snow. 20 km/h south ridgetop wind. Treeline temperature -7 °C.
Tuesday
Mostly cloudy. 5 to 10 cm of snow. 20 km/h south ridgetop wind. Treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.
