Regions
South Coast Inland.
Fresh storm slabs may be primed for human triggers. Start in simple terrain to test the bond of the new snow.
Weather Forecast
FRIDAY NIGHT: Snow; 5-10 cm. / Strong, southwesterly winds / Low -8 / Freezing level 600 m.SATURDAY: Mix of sun and cloud / Light, westerly winds / High -9 C / Freezing level 400 m.SUNDAY: Cloudy with sunny periods and isolated flurries; 1-3 cm. / Light, northwesterly winds / High-18 C / Freezing level surface.MONDAY: Mostly sunny / Light, northwesterly winds / High -18 C / Freezing level surface.
Avalanche Summary
No avalanches were reported in the region on Thursday. However, fresh storm slabs are likely to remain reactive to human triggers on Saturday.
Snowpack Summary
15-30 cm of new snow with moderate southwesterly winds have covered a variety of snow surfaces. These include crusts on all but northerly aspects, wind-pressed surfaces on northerly aspects in the alpine, and a mixture of surface hoar (weak feathery crystals) and surface facets (sugary grains) in terrain sheltered from wind/sun at treeline and below.Around 50-80 cm down is a melt-freeze crust to mountain top on southerly aspects, a crust below around 1700 m on all aspects, and feathery surface hoar in areas sheltered by the wind/sun at treeline elevations. The remainder of the snowpack is currently well-settled and strong in most locations.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.