When you're dealing with a strange avalanche problem like we currently are in the South Rockies, your best option is to reign your terrain choices way in. Stick to simple terrain free of overhead hazard Sunday.
Confidence
Low - Due to the number of field observations
Weather Forecast
A major storm has made landfall on the coast which should drive increasing winds and scattered flurries in the South Rockies. SATURDAY NIGHT: Moderate to strong W/SW winds. SUNDAY: Isolated convective flurries but no significant accumulations expected, freezing level at valley bottom, strong to extreme SW winds. MONDAY: 1 to 5cm, freezing level at valley bottom, light variable winds. TUESDAY: No significant precipitation expected, freezing level at valley bottom, light variable winds. For more detailed mountain weather information visit: avalanche.ca/weather
Avalanche Summary
On Friday numerous loose dry avalanches ran naturally to size 1 on east through southeast facing features around 2250m. On Thursday control work produced numerous small loose snow avalanches within the recent storm snow. On Wednesday we received a report of a skier triggered size 1 wind slab on a north aspect at 1800m. It's thought that this avalanche failed on the December 9th melt freeze crust which was down 40cm at the location of the avalanche.
Snowpack Summary
We're not getting much info from the South Rockies (SoRo) right now, so the following is based almost entirely on observations from the neighboring Lizard Range where the snowpack has been spooky, and to be honest, I'm not totally sure why. Part of the reason is that we're flying blind with regard to the wind direction and speed, all the anemometers in the region are rimed up and not reporting. Here's what I know: Up to 50cm of storm snow has fallen in the last week. It's been cold and this snow remains quite low density. Below treeline it sounds like it's still unconsolidated, but at and above treeline winds from the north and now south/southwest have added a touch of cohesion and the slab remains sensitive to both human triggering and natural failure. Strong SW winds from a week ago formed cornices that began failing on Boxing day (in the Lizard Range). The mid-December surface hoar may be present down around 50cm on north facing features below treeline. Below this a strong, thick rain crust is down around 85 to 130cm and it seems to be capping any deeper weaknesses in the lower snowpack.
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.