Regions
Northwest Coastal.
Avalanche danger is expected to remain HIGH as long as the intense storms continue.
Confidence
Poor - Due to limited field observationsfor the entire period
Weather Forecast
Friday: Light to moderate precipitation increasing intensity throughout the day with 10-20cm expected by the evening. Strong westerly winds becoming extreme southerlies, and freezing levels around 600m. Saturday: Heavy precipitation, extreme southwesterly winds and freezing levels as high as 1000m. Total accumulation expected to be in the 50-75cm range by Sunday morning. Sunday: Freezing levels drop, winds calm down and shift to westerly, and precipitation eases off throughout the day as the storm blows over.
Avalanche Summary
Recent observations are limited, but I suspect natural avalanche activity occurred and will continue in response to heavy loading from snow and especially wind.
Snowpack Summary
Most areas received over a metre of new snow since the weekend, and it's still snowing. Fluctuating freezing levels and varying precipitation intensity and wind throughout the recent storms has probably resulted in various weaknesses within upper snowpack. Widespread large surface hoar was also observed on the previous snow surface at all elevations. The mid and lower snowpack is generally well settled and strong with an old rain crust near the ground.
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.
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.