Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
Cariboos.
Wind slabs are adding to the complexity of the avalanche scenario. Conservative terrain selection remains critical.
Confidence
Poor - Due to the number of field observations
Weather Forecast
A ridge of high pressure will maintain mainly dry conditions for Wednesday and Thursday. For both days, expect a mix of sun and cloud with very light flurries and alpine temperatures of about -9. Winds should be light to moderate from the northwest on Wednesday switching to light and southwesterly by Thursday. A moist and warm southwest flow will bring snowfall to the region late Friday with freezing levels creeping up to about 1400m.
Avalanche Summary
We haven't had any new reports of avalanche activity. This may speak more to a lack of observations rather than actual conditions.If you have any observations, please send them to [email protected].
Snowpack Summary
Approximately 100cm of recent storm snow sits on weak crystals which formed throughout early and mid-November. These weak crystals include facets on a hard rain crust, and surface hoar (which may also sit on a crust on steep southerly slopes). Snowpack data from the Cariboo region is very limited at the moment, but I expect these layers are reacting similarly to the North Selkirk/Monashees because the formation conditions were generally the same. Recent snowpack tests suggest these layers can still be human triggered, and if triggered, are capable of producing wide propagations and large avalanches. Recent variable winds may have redistributed surface snow creating dense wind slabs in exposed terrain.
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.