Regions
Northwest Coastal.
It's easy to feel euphoric when the snow is deep, it's sunny, and you're out with your buds. Be careful not to let that mind set lead you out of conservative terrain Monday.
Weather Forecast
Looks pretty pleasant Monday and Tuesday. The freezing level should stay at the valley bottom, there will likely be periods of sunshine and winds should be light at all elevations. The next storm system starts to affect the region Tuesday night. This one is a bit warmer, the freezing level should increase to around 1500m, winds are once again expected to be extreme SW at ridgetop and 5 to 10cm are expected Tuesday Night. Look for another 5 to 15cm Wednesday and another 5 to 15cm Wednesday night.
Avalanche Summary
Scanning the facebook posts it sounds like at least two folks were involved in avalanches Saturday. Control work Saturday produced slab and loose dry avalanches to size 2.5 from virtually all aspects and elevations. It sounds like a lot of these were running on mid storm instabilities.
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. Initial observations are limited, but there are reports of 75 cm of wind affected snow 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.