High avalanche danger is expected to continue for another day due to new storm slabs, high freezing levels, and above freezing air trapped in the alpine.
Summary
Confidence
Fair - Freezing levels are uncertain
Weather Forecast
Snow ending overnight with a chance of flurries during the day Wednesday. Light SE winds overnight becoming moderate Southwest during the day Wednesday as freezing levels rise up to 1200 metres and some above freezing air becomes trapped between 2000 and 2500 metres. Gradual clearing with some convective snow flurries on Thursday and freezing levels dropping down below 1000 metres. Mostly clear skies with light winds and no precipitation on Friday.
Avalanche Summary
Some large settlements and skier triggered avalanches to size 1.0 were reported from Monday. I suspect the new storm slab has settled with the warming temperatures and may become easier to trigger.
Snowpack Summary
10-20 cm of new snow overnight has developed a storm slab that is 40-60 cm thick that is sitting above a mix of old surfaces including wind slabs, old storm slabs, and pockets of surface hoar. Warm air in the alpine and at treeline has settled the new storm slab into a cohesive slab that is easier to trigger and may allow for longer fracture propagations. Below the storm slab there is a weak layer of surface hoar and crust that was buried in mid-December that continues to be a concern for human triggering. The mid-December weak layer may be buried up to 100 cm deep. Avalanches releasing on this layer may be large and destructive.
triley,
Avalanche Canada
