Wind slabs continue to be the primary concern. Watch for signs of recent wind loading and use extra caution in wind exposed terrain.
Weather Forecast
On Sunday, mostly cloudy conditions are expected with the potential for light flurries. Alpine winds are expected to be strong from the west to northwest and treeline temperatures are forecast to be around -15C. Light snowfall is forecast for Monday with models currently showing around 5 cm. Alpine winds should remain strong but shift to the southwest and treeline temperatures will climb to around -10C. A break is expected Monday overnight before another pulse of light snowfall on Tuesday.
Avalanche Summary
On Friday, ski cuts produced several size 1 wind slabs which were 5-20 cm thick. On Thursday, a natural size 2 wind slab occurred in the Corbin area. This occurred at 2000m elevation on a northeast aspect as a result of recently strong southwest winds. Check out the MIN post for more details and a photo. Ongoing strong winds are expected to continue on Sunday. Recent winds have been from a variety of directions and wind slabs should be expected on most aspects in wind exposed terrain.
Snowpack Summary
Ongoing strong alpine winds have formed wind slabs in exposed terrain. The prolonged cold temperatures have been causing widespread surface faceting and in sheltered areas, surface hoar formation is reported. A layer of surface hoar from early December is reported to be down 20-40 cm in the southeast of the region. The thick mid-November crust layer is buried near the bottom of the snowpack and recent tests suggest it is generally well bonded to the adjacent snow. Below treeline, the snowpack is very shallow and early season hazards such as stumps, rocks, and open creeks are still a major concern.
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.