Regions
Northwest Coastal.
Avalanche danger is increasing as new snow and strong winds incrementally load the snowpack. Reports from higher elevations have been limited and it remains essential to supplement this forecast with your own observations and safe travel techniques.
Confidence
Low - Forecast snowfall amounts are uncertain
Weather Forecast
Sunday: Flurries bringing 5-15 cm of new snow. Moderate to strong south winds. Freezing level to 1000 metres with alpine temperatures of -3.Monday: Periods of snow bringing approximately 15 cm of new snow, increasing over the day. Strong south winds. Freezing level to 1000 metres with alpine temperatures around -2.Tuesday: Flurries brining 10-15 cm of new snow. Moderate to strong southwest winds. Freezing level around 1000 metres with alpine temperatures around -2.
Avalanche Summary
Reports from Wednesday included observations of several natural wind slab releases from steep, north-facing alpine terrain in Bear Pass. These were triggered by rain. Reports from Sunday showed evidence of a natural loose wet avalanche cycle focused on steep, low elevation rock slabs along Highway 16 between Terrace and Prince Rupert. Observations of high elevation terrain have been very limited. Please post your observations to the Mountain Information Network (MIN)
Snowpack Summary
Snowpack depths at treeline elevations average about 70-130 cm in the south of the region. Here, an elevation dependant 20-40 cm of new snow from last week's storm now forms the upper snowpack. Moderate to strong alpine winds during and since the storm encouraged the formation of storm slabs in the new snow. These slabs will increase in size and sensitivity in wind-exposed areas. A thick rain crust that formed early last week exists below the new snow and has produced hard results in snowpack tests. Below this crust, two weak layers are noted to have formed during the early season. (October 31 and November 11). The deeper late October layer has produced moderate to hard results in targeted snowpack tests. Beneath it, the bottom 20 cm of the snowpack features loose, sugary crystals that have begun to show signs of improved bonding. Looking further to the north of the region near Ningunsaw, the snowpack is starkly different. Here, much drier, colder early season conditions produced a shallow snowpack composed mainly of weak, sugary snow. Snow depths in this part of the region are largely below threshold depths for avalanching.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.