Avalanche Forecast

Numerous natural and human-triggered storm and slabs (up to size 2) were reported lately in Revelstoke area.

Continued very large natural and human-triggered persistent slabs (size 2 to 3) failing on a widespread weak layer underneath the storm snow. Some were remotely triggered. Few stepped down to deeper buried weak layers and even down to the ground. Many of these human-triggered avalanches were a surprise to the individuals triggering them.

Although natural avalanche occurrences seem to be tapering off, the next round of precipitation may increase the likelihood of triggering. Please continue to share any observations or photos on the Mountain Information Network.

Up to 15 cm of light snow is now overlying 30 to 60 cm of dense storm snow. Under it, there is a wide variety of previous surfaces; sugary faceted grains, cold unconsolidated snow or a small surface hoar.

New snow has been redistributed at higher elevations on northerly aspects, and fresh slabs may not bond well to older surfaces. At lower elevations, a significant rain crust can be found.

In the upper snowpack, up to three weak layers created earlier in December can be found. Some of these may not exist in all areas of our region. The November weak layer, which will continue to be a concern even after this past storm, can be found anywhere between 75 and 125 cm down. The bottom of the snowpack is generally weak and faceted.

A stronger coastal system will spread moderate snowfalls into the region until later Friday through the weekend. Greater amounts are expected in the western sections. An upper ridge will be bringing widespread subsidence, and therefore fair weather conditions are expected for Monday.

Friday night

Snow, 5 cm except around 10 cm over the Monashees and Cariboos southwesterly ridge winds up to 45 km/h, treeline temperatures -5 °C. Freezing level around 500 m.

Saturday

Light snow, 5 cm except around 10 cm over the Monashees and Cariboos, southerly ridge winds up to 40 km/h, treeline temperatures -5 °C. Freezing level around 750 m.

Sunday

Cloudy, lingering flurries, northwesterly ridge winds up to 20 km/h, treeline temperatures -5 °C. Freezing level around 500 m.

Monday

Mainly sunny, no precipitation, southwesterly ridge winds at 20 km/, treeline temperatures around -8 °C. Freezing level at valley bottom.

More details can be found in the Mountain Weather Forecast.

• Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
• Be carefull around freshly wind loaded features.
• Choose conservative terrain and watch for clues of instability.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.