Forecast snowfall amounts vary greatly across the region with areas to the far south and west expecting the highest accumulations. Pay close attention to how much snow falls in your area, and be prepared to back off to simple terrain.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain on Monday
Weather Forecast
In most areas 10-15cm of snow is expected to fall between Sunday night and Monday afternoon, although more than double that amount may fall in the far south and western parts of the region. Generally overcast skies and light flurries are forecast for Tuesday and Wednesday. Ridgetop winds will be moderate to strong from the southwest on Sunday night and Monday, and then become light on Tuesday and Wednesday. Freezing levels will hover around 1400m on Monday and Tuesday, and then drop to about 1200m by Wednesday.
Avalanche Summary
On Friday, there was an anomalous size 2.5 slab avalanche on an unsupported rocky face on the northwest corner of Mt Fissile (in the Fitzsimmons Range) at about 1900m. Although the sliding layer is unknown, the avalanche was thought to have been triggered by warming. There have also been numerous reports of solar-triggered cornice falls. Some cornice falls have been large (up to size 3), but most have only entrained surface snow. New snow and wind on Sunday and Monday will create new wind slabs at higher elevations while rain will promote a round of loose wet avalanche activity below treeline.
Snowpack Summary
New snow and moderate winds on Sunday and Monday will form new wind slabs at higher elevations. Below treeline, rain will saturate the upper snowpack. The new snow will overlie a sun crust on sun-exposed slopes, dry settled powder on shady slopes, and pockets of fresh wind slab in lee and cross-loaded terrain near ridge crests. Below the new snow the snowpack is strong and well-settled throughout with no notable persistent weaknesses. Cornices are reported to be large and fragile.
jlammers,
Avalanche Canada
