Although the likelihood of triggering a persistent slab has decreased, the problem still exists. Continue to employ a conservative approach to terrain selection.
Confidence
High - The weather pattern is stable
Weather Forecast
MONDAY: Mainly sunny / light to moderate east wind / alpine temperature -4 CTUESDAY: A mix of sun and cloud / light to moderate southeast wind / alpine temperature -3 CWEDNESDAY: Mainly cloudy with scattered flurries / light to moderate southeast wind / alpine temperature -3 C
Avalanche Summary
There have been no new reports of avalanche activity in the past few days.
Snowpack Summary
In exposed areas the upper snowpack has been wind affected and stiff wind slabs exist. In sheltered areas you can still find pockets of low density snow. A crust and in some places surface hoar can be found down 50 cm below the surface. Approximately 60-110 cm below the surface is a layer of sugary facets sitting on a crust that continues to be reactive in snowpack tests, especially on north aspects. This layer seems to be more reactive in the North Shore Mountains. The problem is not typical for the region and we expect this persistent layer to linger into the future. The lower snowpack is generally strong.
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.