Strong SW winds and 30cm of snow will increase the avalanche danger to High on Wed. Buried surface hoar was found in sheltered north aspects Monday. Take the time to understand the complexity of the snowpack right now before jumping onto any slope.
Weather Forecast
Up to 30cm of snow is forecast over the next 48 hours, starting mostly Tuesday afternoon. Warming to above freezing at valley bottom with continued strong SW winds. Winds backing off and temperatures cooling by Thursday.
Snowpack Summary
Jan 5 suncrust/surface hoar layer is now down 15-30cm. SH up to 15mm was found on sheltered N locations. Strong SW winds building new slabs with lots of storm snow available for transport. S and W slopes predominantly scoured with crossloaded features. Buried windslabs lingering in open areas treeline and above produced by moderate SW winds Dec 28.
Avalanche Summary
No new observations but poor visibility. Suspect sluffing out of steep lee terrain with strong SW winds.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
Problems
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.
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.