Seek out areas of sheltered powder for the best quality, safest skiing and riding. Wind loaded features may still react to human triggers, and especially to heavier triggers like cornices.
20 to 35 cm of recent snow and strong southwest winds formed wind slabs on lee aspects at upper elevations. These slabs are most likely to be reactive on steep slopes immediately below ridgetop.
Cornices have been described as large and overhanging in the Purcells. Cornice failures are dangerous in their own right, but they could also trigger very large and destructive persistent slabs.
On Thursday, explosives control north of the Bugaboos produced three persistent slabs, size 2 to 3.5, the largest of which propagated widely and ran full path. It wasn't possible to positively identify their failure planes.
A size 2 cornice and size 2 storm slab were among the explosives results, all of which occurred at 2600 m or higher. A few small explosives triggered and natural wind slabs occurred east of Invermere.
If you are heading into the backcountry, post a MIN!
Light flurries are slowly adding to 20 to 35 cm of recent snow, which was affected by moderate to strong southwest wind and has in some areas formed slabs on lee aspects.
Where sheltered, the recent snow is settling and bonding well to a thick crust found on all aspects up to at least 2200 m.
Various persistent weak layers may still exist in the top 150 cm of the snowpack. Triggering very large persistent slabs on these layers may be possible at upper elevations where the crust below the recent snow is thin or absent. Large triggers, like falling cornices, are the most likely to trigger these weak layers.
In shallow snowpack areas, depth hoar (large facets) can be found near the bottom of the snowpack.
Saturday Night
Partly cloudy with scattered flurries bringing 2 to 5 cm of new snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Sunday
A mix of sun and cloud with isolated flurries and up to 3 cm of new snow. 40 km/h southwest ridgetop wind, easing late afternoon. Treeline temperature -6 °C.
Monday
A mix of sun and cloud with overnight flurries easing with up to 5 total cm of new snow. 30 km/h west ridgetop wind. Treeline temperature -9 °C.
Tuesday
Mainly sunny. 30 km/h south ridgetop wind. Treeline temperature -8 °C.
More details can be found in the Mountain Weather Forecast.
