Variable conditions exist across the region. Be your own forecaster and make observations continually as you travel.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Wednesday
Weather Forecast
On Tuesday expect overcast skies and trace amounts of new snow. By Wednesday morning, light snowfall will develop and continue until Thursday morning bringing 5 to 8cm of new snow. Ridgetop winds associated with the snowfall will be strong and southwesterly. Freezing levels may peak at about 1200m on Wednesday, but should otherwise remain at or near valley bottom for the rest of the forecast period.
Avalanche Summary
Explosives control on Saturday triggered a size 1 wind slab in the south of the region. No other recent avalanches have been reported in the South Rockies region. Several avalanches were reported in the Lizard/Flathead region on Thursday and Friday. The primary problem in that region is wind slabs failing on the early January surface hoar layer. Similar conditions may exist in some parts of the South Rockies.
Snowpack Summary
The Avalanche Canada field team has been finding variable conditions across the region. East of Crownest Pass the snow surface is now widely wind affected. Extensive scouring has been reported in some areas and and stiff wind slabs exist in lee features at treeline and in the alpine. In areas that have seen less wind, recently formed wind slabs are likely softer, deeper and may overlie weak surface hoar crystals which formed at the start of January. In either case, snow pit tests in wind loaded features show recently developed slabs are failing under moderate loads and can propagate over wide distances. The early December crust can be found down around 60-90cm. It is not currently expected to pose an avalanche problem but could wake-up in the future with substantial warming or heavy snow loading.
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.