Snowfall amounts are variable and uncertain for Sunday night. Watch for wind slabs at higher elevations.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Monday
Weather Forecast
SUNDAY NIGHT: Unstable weather will bring spotty precipitation with 0-20 cm of snow possible, gusty winds, and freezing level dropping to the valley. MONDAY: Cloudy with some lingering flurries in the morning then clearing in the afternoon, light north winds, freezing level climbing to 1600 m.TUESDAY: Sunny, moderate west wind, freezing level up to 2000 m after an overnight freeze.WEDNESDAY: Sunny with patchy clouds, moderate west winds, freezing level climbing to 2500 m with little overnight freeze.
Avalanche Summary
No new avalanches reported. On Friday, there were numerous loose wet avalanches up to size 2 at all elevations on solar exposed aspects in the north Elk Valley area.On Monday, fresh storm slabs are the primary concern. Deep persistent slabs will become a growing concern throughout the week as temperatures warm up.
Snowpack Summary
Expect a wide range of new snow amounts on Monday morning. The new snow will sit above a mixture of crusts and moist snow surfaces that formed with the recent warm temperatures and solar radiation. Wind slabs are a possible at higher elevations, where the warming effect has been less dramatic. The bottom third of the snowpack is composed of weak facets and full-depth avalanches over this basal weakness remain a concern, and may be triggered by large loads like cornice falls, or strong solar radiation on a clear day.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.