Cautious terrain selection and good group management are essential right now. A touchy layer, with remote triggering potential means that you need to be aware of who is above and below you, minimize your exposure, and regroup in safe spots.
Weather Forecast
Today expect a mix of sun and cloud, with a high of -6'C and light to moderate SW winds. Light flurries are expected to begin overnight and continue through Thursday with freezing levels rising to 1400m. On Friday the first of a series of fronts moves into the region. Up to 30cm of snow are forecast by Saturday morning with strong W'ly winds.
Snowpack Summary
78cm fell over 5 days, settling into a 60cm lab over the Jan 15 SH. This slab will be deeper in lee features where it has been windloaded by moderate S winds. This surface hoar was widespread, observed well into the alpine and on solar aspects sits on a sun crust. The December 17 surface hoar layer is down 100-150cm sitting on a crust below 2100m.
Avalanche Summary
Artillery control yesterday triggered over 30 size 2 to 3.5 avalanches from all aspects between 17-2700m. Notables were size 3.5's from the W face of Cheops and off Mt Tupper that ran into the creeks. Avalanches up to size 3 have been observed in the backcountry. Human triggered avalanches continue in the region with remote triggering up to 300m.
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.
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.