Regions
Northwest Inland.
Warming forecast for the next few days will destabilize the snowpack. Use extra caution if the sun makes an appearance.
Confidence
Moderate - Freezing levels are uncertain on Monday
Weather Forecast
On Monday, expect 1-5mm of precipitation with freezing levels climbing from 1600m to 2100m throughout the day. On Tuesday the region will see a mix of sun and cloud with freezing levels shooting to 2800m. Light snowfall is forecast for Wednesday. Ridgetop winds are forecast to remain strong from the southwest for the entire forecast period.
Avalanche Summary
In the Smithers area on Saturday there were reports of a few naturally triggered wind slab avalanches to size 2 on east and southeast aspects at about 1700m. Continued snow and wind on Sunday will promote ongoing wind slab activity with the potential to step down to deeper, more destructive persistent weak layers.
Snowpack Summary
New snow and wind on Sunday has created reactive new wind slabs throughout the day adding to an ongoing wind slab problem. New snow accumulations will also add mass and reactivity to a developing slab which overlies recently buried surface hoar. This layer was observed in the Hankin area and may exist in many other places. The early or mid January surface hoar layer is generally 30-50 cm deep, although it may be buried by up to 100cm of snow in the far west of the region. Observers have found this persistent weakness on all aspects and at all elevations. It consistently produces moderate "pops" results in snowpack tests. Below this, the Boxing Day surface hoar problem may also be lurking. The mid and lower snowpack is generally quite weak and faceted, especially in lower snowpack areas such as the Babines.
Problems
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.
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.
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.