Regions
Northwest Inland.
Caution as you transition into wind exposed terrain, some new snow combined with winds that have been blowing from a variety of directions have developed wind slabs on a variety of aspects.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
SUNDAY NIGHT: Cloudy with scattered flurries, moderate southwest winds, alpine temperature -13 CMONDAY: Mix of sun and cloud, moderate west winds, alpine temperature -10 CTUESDAY: Mainly cloudy, moderate southeast winds, alpine temperature -11 CWEDNESDAY: Flurries with 5-10 cm accumulation, moderate southeast winds, alpine temperature -9 C
Avalanche Summary
There have not been any recent reports of avalanche activity in the south of the region. Reports from Ningunsaw in the far north of the region on Friday, show explosives controlled avalanches running to size 2.5 with evidence of a previous natural avalanche cycle that was suspected to have happened during the storm earlier in the week. These avalanches were suspected to run on a weak layer of feathery surface hoar buried in late December and some were reported to have failed to the ground.
Snowpack Summary
10-15 cm of new snow over past two days along with moderate to strong and variable winds have produced variable surfaces at treeline and alpine elevations. Expect to find wind-scoured surfaces as well as wind slabs in lee terrain features. Below treeline, expect to find a melt-freeze crust near the snow surface.Buried under recent storm snow, you may find a few weak layers in sheltered areas comprising of feathery surface hoar crystals and/or sugary faceted snow. The upper layer was buried around December 31 and is about 20-30 cm deep. The next layer may have been buried around December 22 and is likely 40-60 cm deep. The lower one was buried in early-December and is now approximately 80-120 cm deep. The bottom 30 to 50 cm of the snowpack consists of weak and sugary faceted grains and crusts, particularly in areas where the snowpack is thin. It is possible that shallower avalanches could scrub down to ground in these thin snowpack areas, due to this weak layer at the base of the snowpack.
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.