Regions
Northwest Coastal.
The danger has come down slightly, but the snowpack needs more time to adjust before we start to size up more challenging objectives.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Clear and dry weather is forecast for the period. No precipitation is expected. Winds should decrease Saturday afternoon, but they remain strong SW at upper elevations Sunday. Monday and Tuesday look the same, but all bets are off for Wednesday. The current models show the freezing level rising to 2000m. Too early to say how that will play out.
Avalanche Summary
I suspect large natural avalanches were running Friday, but we do not have any observations from treeline/alpine elevations where the action is at.
Snowpack Summary
The NW Coast is THE place to be in the province right now. Arctic air has kept things cool and the snow totals are substantial. The storm produced 50 to 100cm accompanied by screaming winds out of the E through SE. Observations are limited, but there has likely been a lot of slab development in wind exposed terrain at and above treeline. The late-January crust is thought to be down 50 to 150cm in the south of the region and about half this depth in the north. This crust may have surface hoar on it. The mid-January rain crust and/or surface hoar layer is down over 150cm in the south and has generally become inactive though it may still be a concern in thinner snowpack areas. The November crust/facet combo near the bottom of the snowpack is thought to be generally well bonded but may still be reactive in the far north of the region.
Problems
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.