Good skiing can be found on low-angled terrain above treeline. The snowpack remains generally shallow and weak, a little less so to the West. Do not lose sight of the unpredictable nature of the deep persistent slab problem even though conditions appear to have improved.
The lower snowpack is comprised of weak facets and depth hoar with the upper snowpack forming a 40 to 90cm thick slab above. This weak basal layer is uniform across most of the forecasting region and has been responsible for most of the avalanche activity to date this season.
A few small surface avalanches triggered by explosives were reported by Lake Louise and Sunshine patrol on Wednesday. Tuesday, a Sunshine patroller triggered a size 2 deep persistent slab while skiing the slope after getting no result with explosives. No burial or injuries.
Flurries over the last 10 days total to roughly 10cm settled, with little wind effect. The Dec 17 surface hoar/sun crust layer is visible down 25-50 cm, but generally not reactive. The Nov 16 deep persistent layer is down 40-90 cm and continues to produce sudden failures in snowpack tests. In Little Yoho, these two layers are deeper and more spread apart in the snowpack.
Thursday morning flurries, bringing 2-4 cm, will taper through the day as skies clear with the passage of an upper trough. Winds will be 20-40 km/hr and alpine temperatures will rise to near -5C. Thursday night temperatures fall to -10 to -15C. Skies clear for Friday.
More details can be found in the Mountain Weather Forecast.
