New snow and wind on Monday will create touchy storm slabs reactive to human triggers; especially in wind effected terrain.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
MONDAY: Snow, accumulation 10-20 cm. Moderate to strong easterly ridgetop winds. Alpine temperature -1. Freezing level around 1500 m.TUESDAY: Snow, accumulation 5-10 cm. Moderate southwesterly ridgetop winds. Alpine temperature -1. Freezing level around 1500 m.WEDNESDAY: Mostly cloudy with sunny breaks. Light southwesterly ridgetop winds. Alpine temperature +1. Freezing level rising to around 1700 m.
Avalanche Summary
Several loose wet avalanches up to size 2.5 which were triggered by cornice falls were reported near Fernie on Sunday. Storm slab avalanche activity will likely increase with the forecast snow on Monday.
Snowpack Summary
15-25 cm of new snow and moderate winds have formed storm slabs reactive to human triggers. This storm snow overlies numerous crusts in the upper 100 cm of the snowpack.The mid-pack is generally well settled and strong.A layer of sugary facets around a crust can be found near the bottom of the snowpack which has been dormant for some time. Large triggers, such as a falling cornice, or a major warm-up to the snowpack could trigger this layer.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.