Purcells

 While avalanche conditions have improved, it may still be possible to trigger large avalanches on deeply buried weak layers. Be careful with your terrain selection, especially around steep rocky terrain.

THURSDAY NIGHT: Clear skies above valley cloud, light to moderate wind from the west, treeline temperatures drop to -10 C.

FRIDAY: Clear skies above valley cloud, moderate wind from the west, treeline temperatures around -3 C with a possible inversion.

SATURDAY: Clear skies above the valley cloud in the morning and then increasing high clouds in the afternoon, moderate wind from the southwest, treeline temperatures around -6 C.

SUNDAY: Cloudy with isolated flurries and trace amounts of snow, moderate wind from the southwest, treeline temperatures around -8 C.

Since Monday there have been a few reports of size 2 slab avalanches that were either triggered by wind loading or cornice falls. This activity has been tapering.

Two weeks ago there was a notable cycle of very large (size 2.5-3) avalanches failing on the early December persistent weak layer. We continue to get reports of avalanches that occurred during this cycle. There were a few reports of human triggered avalanches on this layer last weekend in the northern Purcells including this report from Quartz Creek last Friday, Hospital Creek (just outside the region) on Saturday, and a smaller skier controlled avalanche in shallow location near Invermere on Saturday. Most of these avalanches occurred at elevations around 2000 m. Although activity on this layer has recently tapered, possible natural triggers could be daytime warming, sun, cornice falls or smaller avalanches. Human triggering could be possible in steep rocky slopes with a shallow or thin-to-thick snowpack.

Recent weather has formed surface hoar crystals in sheltered areas and possibly sun crusts on solar aspects. These will become important layers to track once buried by new snow. Alpine terrain has variable wind effect. Some older thin surface hoar layers are 20-40 cm deep, but have not been producing concerning results in recent snowpack tests. The most notable layer of concern in the snowpack is a crust/facet layer that formed in early December and ranges in depth between 70 cm along the shallower eastern Purcells up to 150 cm in the western Purcells.

• In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
• Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
• Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.