Regions
Northwest Coastal.
Confidence
Fair - Intensity of incoming weather is uncertain on Monday
Weather Forecast
Saturday: Expect mostly cloudy skies, with a chance of isolated flurries. Winds should be light from the west with alpine temperatures reaching -2.Sunday: Expect a mix of sun a cloud. Again, occasional light flurries are possible; likely confined to the northern half of the region. Winds should remain light from the west-southwest with alpine temperatures reaching -2.Monday: Flurries are likely to build over the day, with continued light west-southwest winds and alpine temperatures around -4.
Avalanche Summary
Avalanche activity has slowed but natural and rider triggered events are still being reported. Natural releases up to 2.5, predominantly in windloaded alpine and treeline locations and small accidental events (no involvements) have occurred. Loose wet sluffs at low elevations persist.
Snowpack Summary
Recent weather has been relatively benign, with precipitation pulses giving incremental loading (5-10cm at a time). Relatively light winds have accompanied these snowfall pulses with some stronger outflow winds closer to the coast. At lower elevations (below 700m), the drizzly rain is saturating and eroding the snowpack.Previous strong southwest winds gave intense snow transport and cornice growth. Extensive windslabbing in lee zones and behind ridges in the alpine and treeline was the result. Some areas saw swirling winds resulting in some cross and reverse loading on southeasterly features. These significant windslabs are now lightly buried.In the upper snowpack, various melt-freeze crusts remain a concern. Depending on your location, you may encounter crusts as shallow as 40cm and as deep as 110cm. Recent compression tests show both resistent and sudden planar results and an extended column test showed a continued propensity for propagation if the layer was triggered. It is certainly worth keeping these layers on your radar in regards to distribution and reactivity in the areas that you are riding. The mid and lower snowpack is generally well settled..
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.