Wind effect remains the critical factor. The safest and likely best riding will probably be found in wind sheltered low elevation terrain.
Confidence
Moderate - Freezing levels are uncertain on Tuesday
Weather Forecast
The freezing level is expected to remain at valley bottom through Monday as cold dry air sits in the valleys of the Purcells. But, a significant meteorological change is expected Monday night as warm air floods into the region. Current models show the freezing level rising to around 2500m Monday night as strong to extreme winds blow out of the southwest. Very little precipitation is expected with this change. SUNDAY: Freezing level at valley bottom, no precipitation, moderate west/southwest wind. MONDAY: Freezing level at valley bottom for most of the day, rapidly rising in the late afternoon, possibly as high as 2500m. No significant precipitation expected, winds steadily increasing out of the west/southwest. TUESDAY: Freezing level around 2300m, 1 to 3mm of precipitation expected, strong southwest wind.
Avalanche Summary
On Friday small wind slabs were triggered by skiers on a variety of aspects. Control work in the central portion of the region produced small wind slabs in north facing terrain around 2400m. On Thursday, a natural size 2 wind slab avalanche was reported from a North aspect near 2500m. Explosive triggered cornice drops initiated numerous slab avalanches size 2.5 and one size 3 on the slopes below. They were initiated from NE through S aspects above 2500m. The details of these larger avalanches did not state if they were persistent slabs or wind slabs. Regardless, the size and magnitude is very destructive.
Snowpack Summary
15 to 30 cm of recent snow has been formed into reactive wind slabs on a variety of aspects. These new wind slabs rest on an old surface consisting of ageing wind slabs in exposed terrain, surface hoar in sheltered terrain, and widespread "sugary" facets. The layer of facets from mid-December is still reactive to snowpack tests in isolated areas but is generally considered to be dormant during this period of cold, dry conditions. This may change as the air temperature begins to rise as warm air floods into the region next week.
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.