Up to 10cm of new snow and accompanying wind is forecasted to arrive Wednesday. Watch for fresh wind-slab development. Additionally, a deep persistent slab problem is evolving on the Oct 23 crust layer. Keep this in mind moving forward.
Old wind slabs persist and will be further buried by incoming snow and wind on Wednesday. Pay close attention to these in lee areas, as they may step down to buried crust layers in the snowpack.
The Oct 23 crust, found near the ground in the basal snowpack has been associated with avalanches up to size 2. These avalanches have occurred at Sunshine and Lake Louise in the past few days. This layer/problem is something to monitor as the snowpack receives more load.
Lake Louise Patrol reported another deep slab release on the October 23 crust, triggered by explosives. The slide was a size 2. Sunshine patrol observed a size 2 cornice triggered wind slab on an alpine lee feature on Healy Peak. The Visitor Safety field team did not observe any avalanches on 93N.
A few cms of snow over previous wind slabs in exposed alpine and treeline terrain. In the middle of the snowpack the Nov 9 solar/temp crust is present. In some places there is surface hoar on this crust making it more reactive to loading. At the base of the snowpack a crust that formed in late October can be found to ridgetop. Facets are developing around this basal crust. Treeline snow depths range from 40-60 cm with less snow at lower elevations and many thinly buried hazards.
5-10cm of snow will accumulate in the region late Wednesday into Thursday. Temperatures will be generally seasonal, with valley temperatures below 0 and the ridge near -12. The leading edge of the front will be windy, with values as high as 80km/hr from the south, but it will be short-lived and taper off into the moderate range on Thursday.
