Small amounts of new snow will form fresh wind slabs. The lingering possibility of deep persistent slab avalanches warrants extra caution around big open slopes.
Summary
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Sunday
Weather Forecast
SATURDAY NIGHT: Flurries with about 5 cm of new snow in western parts of the region and 2 cm in eastern parts, moderate southwest winds, alpine temperatures around -5 C.SUNDAY: Cloudy with isolated flurries, moderate southwest winds, freezing level around 1500 m.MONDAY: Cloudy, strong southwest winds, freezing level around 1400 m.TUESDAY: Flurries with 5-10 cm of new snow, strong southwest winds, freezing level around 1700 m.
Avalanche Summary
Recent avalanche observations are limited. Earlier in the week, there were isolated reports of size 2 natural deep persistent slab avalanches around Waterton and Elkford. A few size 1-2 loose wet avalanches were reported at lower elevations during Thursday's storm, but cooling temperatures have improved the stability of the old storm snow. On Sunday, watch for fresh wind slabs at higher elevations. Also keep in mind that the deep persistent slab problem is a low probability/high consequence scenario that warrants extra caution around large open slopes, especially in shallow snowpack areas.
Snowpack Summary
Expect light amounts of new snow on Sunday with moderate to strong southwest winds forming thin wind slabs in exposed terrain. The new snow sits above settled snow and hard rain crusts below 1900 m. The midpack consists of 50-100 cm of settled snow from last week's storm. In deep snowpack areas, the lower snowpack appears to be well settled with only isolated concerns about the mid-December facet layer which comprises the bottom third of the snowpack. In shallow snowpack areas, this layer is weak and faceted.
Watch this video from the South Rockies field team for some recent test results on this layer.
shorton,
Avalanche Canada
