Regions
Northwest Coastal.
Cool and stable weather should mean a gradually strengthening snowpack.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
Wednesday: Dry with some clear spells until late in the day. Strong northwesterly winds. Models indicate an inversion will set up for Wednesday afternoon with valley temps around -10C and above-zero between 1400m and 2000m. Thursday: Light snow, 2-5 cm expected, clearing thorough the day. Winds initially strong northwesterly but diminishing through the day. Treeline temps around -8C. Friday: Cold and dry. Moderate and locally strong easterly winds. Treeline temps around -12C.
Avalanche Summary
The north part of the region reported up to size three natural avalanches over the weekend. Poor visibility limited observations in the south but no new avalanches were reported.
Snowpack Summary
The region picked up 20 to 60cm of storm snow over the weekend accompanied by winds out of the southwest, west, northwest, and most recently the east. This will have set up storm slabs in more sheltered areas and wind slabs on a wide variety of aspects in more exposed areas. These new storm and wind slabs may rest on a melt freeze crust (reported to be 3 to 15cm thick), and there are reports there also may be surface hoar resting above this crust in sheltered locations. Below this crust the mid-pack is reported to be generally strong. You can expect to find a second prominent crust, which was buried at the end of October, 100 to 200cm below the surface. This lower layer may have associated facets, particularly in more shallow locations.
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.