Watch for pockets of stiff wind slab at upper elevations from recent northerly outflow winds. These slabs may be in atypical areas due to reverse-loading and could be particularly reactive where they overlie a slick crust.
This week's storm snow totals 40 cm in the alpine. Northerly outflow winds are redistributing available snow into fresh wind slabs in lee south aspect terrain. Wind slabs may be reactive to human triggering where they overlie a slick crust. Seek out sheltered terrain where you can avoid wind slabs and find good riding.
On Wednesday, we received a MIN report of a skier accidental avalanche from Nak Bowl. The avalanche happened when skiing over a convexity and likely released on a crust below the storm snow. A natural size 2.5 wind slab avalanche was also reported from Nak Peak area. This avalanche is suspected to have stepped down to deeper layers. Several loose avalanches were observed up to size 2 on south aspects from solar input and elevated freezing levels.
On Friday, several size 1 loose wet avalanches were observed on steep solar aspects with sun and warm temperatures.
Looking forward to Sunday, riders should be cautious around pockets of stiff wind slab in the alpine and treeline. These slabs may fail easily where they overlie a slick crust and will be in more atypical locations, as northerly winds have created a reverse-loading pattern.
Thank you for all the MINs, please continue to share any observations or photos on the Mountain Information Network.
The past week's storm delivered to this region 30 to 40 cm of new low-density snow. In the alpine and at the treeline elevations storm snow has and continues to be redistributed by a moderate northeast wind. Expect on lee aspect terrain to find pockets of windslab up to 80 cm in depth that overlies a stiff melt-freeze crust.
Generally, the mid and lower snowpack is well-settled. Weak layers exist within the mid and lower snowpack but the thick crusts sitting above them make triggering avalanches on these layers unlikely.
Snowpack depths are 150 to 200 cm at treeline and taper rapidly below 1500 m.
Saturday night
Clear with cloudy periods. Alpine temperatures drop to a low of -15 °C. Ridge wind northeast 30-50 km/h. Freezing level at valley bottom.
Sunday
Sunny. Alpine temperatures reach a high of -8 °C. Mostly light ridge wind occasionally gusting to 40 km/h from the north. Freezing level at valley bottom.
Monday
A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -8 °C. Ridge wind west 15-30 km/h. Freezing level at valley bottom.
Tuesday
Cloudy with sunny periods and isolated flurries. Alpine temperatures reach a high of -5 °C. Ridge wind west 15-35 km/h. Freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
