Strong to Extreme southwest winds have generated some natural activity on the deep persistent layer and will remain elevated through Saturday.
Fresh wind slabs should be anticipated and can be expected to be sensitive to human traffic.
Travel remains poor BTL.
Days are short.
Practice conservative decision making.
SW winds increased to strong values Friday afternoon and are creating new wind slabs in alpine and exposed treeline terrain. New slab development will add to the existing wind slabs formed last week. These slabs will likely be sensitive to skiers in steep terrain.
The bottom 1/4 to 1/2 of the snowpack is weak and consists of layers of surface hoar, facets, depth hoar, and occasionally, a crust . If initiated, larger avalanches can result which hold the potential to run further than expected and reach below treeline elevations.
A large natural was observed today in the alpine on Mount Fairview. This was no likely a result of wind loading and failed next to the ground on the deep persistent layer.
Lake Louise ski patrol remote triggered a size 1.5 wind slab Thursday. The feature was at treeline and was a reloaded bed surface from a previous avalanche.
Last week's storm snow has settled to 20-40cm at treeline. A rain crust up to 7cm thick exists within this storm snow as high as 2300 and has been found to be more extensive in the southern part of the region. Wind slabs are prevalent from previous strong winds.
This upper snow overlies the deep persistent weak layer that consists of surface hoar facets and depth hoar. Treeline snow depths range from 50-80cm.
Click here for the snow profile from Tuesday in the Dolomite peak area.
SW alpine winds will increase into the extreme range Friday night.
Alpine temperature inversions look possible through to Monday morning as do trace amounts of snow.
Winds will shift W /NW and back off into the moderate range Sunday morning before shifting back SW and ramping right back up to strong range in the afternoon.
For more information, click Mountain Weather Forecast.
