Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A weak ridge of high pressure will bring unsettled conditions to the interior regions on Tuesday and Wednesday. The next frontal system is expected to hit the north coast on Wednesday night or Thursday morning and should bring moderate amounts of precipitation to the Cariboos by Thursday afternoon.Tuesday: Mostly cloudy, generally dry conditions but light flurries possible, treeline temperatures around -5C, light to moderate W-NW winds.Wednesday: Mostly cloudy, light flurries 2-4cm, treeline temperatures around -2C, light SW windsThursday: Snowfall 15-25cm, freezing levels rising to 1000-1500m, light to moderate SW winds
Avalanche Summary
No natural activity has been reported since Saturday. On Sunday several explosive and human triggered avalanches were reported up to size 3. This includes a skier remote size 2.5 on a crust/facet interface down 150 cm on a SW aspect at 2300m and a skier triggered size 1.5 wind slab on a NE aspect at 1800m.
Snowpack Summary
Roughly 30 cm of new snow has fallen since Saturday. Winds have been generally moderate to strong from the SW-NW and temperatures have fluctuated. Expect to find touchy wind slabs in exposed lee terrain at and above treeline, and buried rain crusts below 1600 m. A couple buried weak layers (surface hoar or facets) are now down 80-100 cm deep. Snowpack depths vary, but in general 150 cm of snow can be found at treeline, with 100-200 cm in the alpine. In many places we're still dealing with a relatively thin snowpack (thanks to a windy early season) so there's not a whole lot of snow between riders and the sugary snow (facets) near the ground. The basal facet/crust combo has been recently active in parts of the region and continues to give easy to moderate results in snowpack tests.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.