Regions
Northwest Coastal.
Confidence
Poor - Due to limited field observations for the entire period
Weather Forecast
Friday: Broken clouds with some sunny breaks, ridgetop winds west 15 km/hr, and alpine temperatures near -10. Saturday: Increasing clouds as a warm front approaches. Periods of snow will begin in the evening. Winds west and northwest 30-50km/h. Temperatures near -8 in the alpine. Sunday: Light to moderate amounts of precipitation. Winds southwest 40km/h. Temperatures in the alpine -3.
Avalanche Summary
Recent reports indicate natural avalanches to size 1.5. These been running in the most recent storm snow.
Snowpack Summary
Up to 60 cm of new storm snow has fallen over the region in the past 4 days. Recently formed and buried windslabs continue to dominate the upper snowpack. Test results show an easy resistant shear down 30-35 cm and a hard resistant down 80 cm. The mid-pack is gaining strength and is well settled.Digging down deeper, there is an early November facet/crust layer, which sits near the base of the snowpack. Tests done in the Bear Pass area around 1100 m have shown this layer to be unreactive. Testing done in the Shames area on this interface have also shown no results, with moist snow below.Total snowpack depth above 1000 m is 150-200 cm deep. Below 1000 m the snowpack shows a sharp transition from 100 cm dropping to 50 cm, and is generally below threshold.
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.