Regions
Northwest Coastal.
Confidence
Fair - Due to limited field observations
Weather Forecast
A radical above freezing layer is forecasted for Sunday night into Monday. Freezing levels as high as 2800m are possible. A cold front sweeps across the NW coast bringing as much as 30mm to the region Monday afternoon as ridgetop winds build to 80 - 95 km/h out of the W. Freezing levels lower Monday as the cold front moves inland.Cold post frontal air keeps the region dry & cool on Tuesday. Ridge of high pressure rebuilds Wednesday & Thursday with an outflow pattern. Another above freezing layer is forecasted for later in the week.
Avalanche Summary
Control work produced avalanches up to size 4.0 in the northern reaches of the forecast region. There are no reports of human triggered avalanches from the region.
Snowpack Summary
Very strong SW-NW winds may wreak havoc on the snowpack creating scoured areas and soft or hard wind slabs in exposed lee terrain and cross-loaded gullies or terrain features. Coastal areas are reporting a very deep and strong snowpack which is at or near record levels for this time of year. A buried surface hoar layer may be found down 100-150cm near Terrace, but there is no recent information on the presence and sensitivity of this layer.
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.