The Bottom Line:  The main threat for now is stiff wind slabs, from several days of strong NW winds. Any recently wind loaded areas may harbor wind slabs 1-2ft thick which could be triggered by a human (Think cross-loaded gullies, and also aspects lee to the NW wind). These surface wind slabs could also step down to rain crusts or the ground in particularly weak areas. (See Persistent Slab problem below)

Wind loaded slopes and cross-loaded gullies should be avoided or carefully managed. You can tell if a slope is wind loaded by the filled-in, rounded or pregnant shape of the snow. Probe around for hollow, slabby surface snow. Minimize your exposure to these slopes, and always travel one-at-a-time through any suspect areas. Rocks will be a major safety hazard as well, so take it slow and easy, and keep your avalanche eyeballs on, especially in wind loaded areas and convexities!

— We are in an Assessment Mindset regarding the following buried weak layers: —

Midpack Melt Layers and Crusts:

There is a unique weak layer forming in the midpack, about 60cm deep (The “Big Warmup” Layer). It initially was a thick layer of warm melting polycrystals from the Nov 17th warmup, but has since frozen and begun facetting into an unusual weak layer with low predictability.

Observations from 12/1 in the Lutak zone found high strength but good propagation on failures within this layer. We know it to exist at all elevations above 1000ft — even up to the highest summits. We expect this layer (or other midpack crust-facet layers) to be an ongoing issue going forward.

Depth Hoar Formation:

The November cold snaps created basal facets in thin areas above 1000ft. These facets haven’t been active yet, but the possibility still exists that an avalanche could fail at the ground in thin areas with a slab on top. This concern may grow into a deep slab problem over time if these facets weaken into depth hoar.

Pit photo from Lutak zone 12/1, and profile from 11/26.