Don't let sunny skies and good snow lure you into complex terrain. Recent human triggered avalanches have been large. Avalanche danger may be improving as the likelihood of triggering them diminishes, but if you're unlucky enough to do so, consequences can be high.
Recent snow and moderate wind have created deep pockets of reactive wind slab in lee terrain features at upper elevations. There have been several instances of human triggered wind slab avalanches around size 2 in the last few days.
A weak layer of surface hoar that was buried around Christmas is now down about 40-80 cm and is most prevalent at treeline and below treeline. This layer remains at a depth triggerable by skiers, sleds and wind slab avalanches.
A deeper persistent weak layer buried in early/mid-December is now down 90 to 150 cm. The form and distribution are highly variable and have may vary significantly from one valley to the next, and between elevation bands. Triggering these layers require large loads such as explosives or other avalanches in motion. The result of a step down to these layer would be large and destructive.
Friday night: Partly cloudy, light west wind, freezing level valley bottom.
Saturday: A mix of sun and cloud, light southeast wind, alpine high -7, freezing level valley bottom.
Sunday: Increasing cloud, light southeast wind, alpine high -7, freezing level valley bottom.
Monday: Flurries, trace, light to moderate southeast wind, alpine high -6, freezing level 800 m.
Recent avalanche activity has been widespread, large (size 2+), running on a variety of weak layers and triggered both naturally and by humans.
Around 40-80 cm of recent snow sits on a weak layer of surface hoar that was buried around Christmas. This layer is most prevalent at and below treeline. Previous moderate to strong winds have redistributed surface snow, creating wind slabs at wind exposed elevations.
A couple of persistent weak layers buried in early/mid-December are down about 90-150 cm. Generally, they can be found as a layer of surface hoar above in close proximity to a crust/surface hoar layer. The form and distribution of these layers are highly variable and conditions may differ significantly from one valley to the next.
