Forecasted weather will bring heavy precipitation and strong winds to much of our region and will increase the avalanche hazard.
The chance of avalanches is very likely today.
Make conservative choices and back off if you see signs of instability.
Significant precipitation continues to hammer our region. Warm temperatures will have this fall as rain at lower elevations and as heavy wet snow at higher elevations. Moderate to strong southwest winds all also associated with this storm.
A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth.
Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.
Sunday saw an increase in avalanche activity as this most recent weather system touched down in our region. These avalanches were caused by wind slabs and storm slabs.
The wind slabs were triggered naturally, by ski cuts, and by cornice failure. They reached up to size two and were 35 to 40 cm deep when they started. All were in the alpine on a variety of aspects including cross-loaded terrain.
By Tuesday evening up to 60 mm will have fallen in a 36-hour period. Due to recent high freezing levels much of this fell as moist heavy snow or rain. Expect wind slabs to have formed from southwest winds where snow was light enough to be transported.
On southerly aspects and below treeline, there is a widespread cust buried 30 to 50 cm down. On north-facing slopes at treeline and above there may exist a layer of faceted snow or surface hoar in shelter areas. Further down in the snowpack, around 60 cm, a surface hoar layer has been reactive to human triggering. This has occurred primarily in the Selkirks, on northeasterly slopes from 1700 m to 2100 m. Wednesday was the last day that there was any real activity on this layer but this storm may change that.
The mid-snowpack is generally strong but the lower snowpack is a different story. The November facets are still prominent at the base of the snowpack. This layer remains a concern in rocky, shallow, or thin to thick snowpack areas at treeline and above.
Monday Night
Cloudy, 25 to 30 cm accumulation of wet snow, winds southwest 20 to 30 km/h gusting to 50, freezing levels cooling to 1600 m.
Tuesday
Cloudy, 20 to 30 cm accumulation, winds southwest 30 to 40 km/h, freezing levels 1500 m.
Wednesday
Cloudy with sunny breaks, up to 10 cm accumulation by morning, winds west 15 km/h, freezing levels starting at 500 m and climbing to 1500 m.
Thursday
Cloudy with sunny periods, trace accumulation, winds west 10 to 20 km/h, freezing levels climbing back up to 1600 m.
More details can be found in the Mountain Weather Forecast.
