Regions
Northwest Inland.
Winds will be the primary issue in the short term. Seek sheltered terrain and be aware of what is above you.
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
Synopsis: A strong Pacific frontal system will impact the Coast beginning on Sunday morning. Expect moderate or locally heavy snowfall (10-15 cm) and strong SE ridge winds as the moist Pacific airmass battles with the Arctic front. Monday could be a bit drier before another frontal system arrives late in the day or overnight. This pulse should drop another 10-20 cm through Tuesday with moderate SW ridge winds. The freezing level remains at valley bottom with average treeline temperatures between -10 and -15.
Avalanche Summary
There are a couple recent reports of rider triggered wind slabs up to size 1.5 from steep treeline features. No new natural activity has been reported. Expect fresh wind and storm slabs to form as snow accumulates and winds increase this weekend.
Snowpack Summary
Recent winds have been highly variable with strong W-NW winds followed immediately by strong SE-NE winds. Hard and soft wind slabs should be expected on a variety of slopes in open terrain. rain was reported to almost 2000 m on New Years Day in the southern part of the region. Since then there's been around 15-20 cm of new snow. At higher elevations and northern sections there could be around 30-40 cm of recent storm snow. The new snow may be resting on older wind slabs or surface hoar in northern areas. Down 40-70 cm you may find another surface hoar layer, although it appears to be spotty in distribution. Near the bottom of the snowpack is a crust facet combo that was buried in mid-November. This layer is currently dormant and produces variable results in snowpack tests. I suspect it will remain sensitive to new inputs in the form of new snow and wind for the foreseeable future.
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.
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.