Snowfall outperforms expectations as wind continues to load lee areas and deeper weak layers.
Overachieving snowfall amounts combined with moderate to strong south to west winds have continued to create new wind slabs in the alpine and in open terrain at treeline.
Recent snow and persistent strong wind will continue to produce dry loose conditions.
This problem has transitioned from a PS to a DPS given the depth and behavior of recent avalanches. These avalanches are failing on either a Nov crust/facet interface near the ground or on the ground itself. Regardless of the failure plane, any avalanche triggered on this layer will be big.
Lake Louise patrol reported triggering size 1 storm slabs with explosives today. The Parks Canada field team did not observe any avalanches in Kootenay.
Up to 40cm of storm snow in the last 72 hours brings the total snow depth over the December 15 melt-freeze crust (below ~2000m) up to 60cm, however it is settling quickly. Moderate to strong S-W winds continue to develop slabs in the alpine and at treeline. The mid-November facet/crust layers are down 80-140 cm and remain active this week with numerous large natural and explosive controlled avalanches.
Partly clear conditions are expected on Christmas Day. Strong southwesterly winds will persist, transporting snow into lee terrain. Valley temperatures will warm to near 0 °C, while alpine temperatures remain colder near −10 °C.
