Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain on Saturday

Saturday night: 5-20cm of new snow / Variable winds / Alpine temperature of -13Sunday: Overcast skies with light flurries / Extreme northeast winds / Alpine temperatures of -20Monday: Mix of sun and cloud / Extreme northeast winds / Alpine temperatures of -22Tuesday: Mix of sun and cloud / Light north winds / Alpine temperatures of -20

A few days ago, a large human-triggered avalanche was reported from Corbin (near Sparwood) on a wind affected slope in an area where weak facets were present. Evidence of a natural size 2.5 persistent slab avalanche was also noted on a treeline feature in the same drainage. While technically this area is in the Lizard/Flathead region, I feel as though it is indicative of conditions in the South Rockies. Where you get a combination of weak sugary snow lower in the snowpack and a supportive upper slab, conditions are ripe for avalanches to be human-triggered. When the wind picks up again on Sunday, new accumulations from Saturday night will get shifted into lee and cross-loaded features and we can expect an increase in wind slab avalanche activity

Up to 20cm of new snow may fall on Saturday night. Extreme northeast wind are expected to redistribute these accumulations into wind slabs in exposed lee terrain. The new snow will overlie previously formed wind slabs which developed on Friday night and Saturday. In general, there is very little structure to the snowpack, with low-density snow sitting over soft sugary facets. Travel is very challenging as a result. A variable interface that formed during the cold snap in early December can be found buried 30-50 cm deep. This interface consists of weak faceted (sugary) snow and preserved surface hoar in sheltered areas. The interface is likely most reactive in wind-affected terrain where it is covered by hard wind slabs. The snowpack is a generally weak and faceted below this interface, including another weak layer with surface hoar or facets that was buried in early December. Hazards such as stumps, rocks, and open creeks are still a major concern.