The Avalanche Hazard is Moderate, human triggered avalanches are possible! Variable distribution of wind slab in the alpine and buried surface hoar layers at tree line and below demand your attention. Choose low consequence terrain features.
Weather Forecast
The best part of the 'Polar Vortex' is the clear, sunny skies that comes with it! Today will be clear and cold with an alpine high of -17 (feels warmer in the sun in the alpine) with light ridge top winds. A small pulse of snow on Thursday and Friday with clear skies returning for the weekend.
Snowpack Summary
Cold temps promoting surface faceting. ~70cm of storm snow overlies the Jan 17th SH and ~60cm over the Jan 31st layer. Strong winds that came in with the storm redistributed the storm snow in the alpine and exposed areas of TL. Wind slabs and buried crusts exist on specific terrain features depending on aspect and elevation.
Avalanche Summary
No new avalanche observations along the highway corridor yesterday. Report of a skier controlled size 1.5 in the Puff Daddy area two days ago, failing on the Jan 31 SH, ~50cm deep in an open area below tree line. There was a large natural cycle over the weekend with many slides running full path.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.