Sunny skies will make slopes look inviting, especially on northern aspects where conditions are still good. While north slopes seem appealing this is where the greatest uncertainty lies in triggering the deeper instabilities.
Below the recent snow is a 60-100cm slab on the persistent mid-pack Jan/Feb facet layer. Concern exists on high northerly aspects where the March 27 raincrust capping the slab is weak, especially as temperatures warm. Once triggered, it could step down to the basal deep persistent layer.
The problem will develop over the day with solar input and warming temperatures. Surface crusts will need to break down for this problem to emerge.
Lake Louise snow safety explosive tested some lesser worked northerly alpine terrain today. Although the shot didn't release an avalanche, it remoted a slope 40 m away, causing a size 2, 60-80 cm deep.
At upper elevations, on northerly aspects, up to 30 cm of recent snow overlies a supportive snow surface or the prominent March 27 rain crust, from last week's rain event. On southerly aspects, there are few additional crusts near the surface.
Below this, a 70 cm slab of dense snow overlies another 70 cm of weak facets. Test results continue to show weakness and propagation in this layer. This is the main event in the snowpack that should dominate decision-making.
Progressively warmer with each day in the outlook.
Friday: Sunny skies, freezing levels climbing to 2100 m, light westerly wind, and alpine temperatures ~3C.
Saturday: Sunny skies and freezing levels climbing to 2300 m, light to moderate westerly wind
Sunday: Sunny and freezing levels climbing to 2500 m, light westerly wind
Monday - cloud and light flurries move back into the region.
