Regions
Northwest Coastal.
Watch for whumphing and cracking below your feet and continue to make observations while gaining elevation towards alpine terrain. If the sun pokes out it may initiate a natural avalanche cycle in the recent storm snow.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
Sunday: Mix of sun and cloud with snow amounts 2-5 cm. Ridgetop wind strong from the southwest. Alpine temperatures near -3 and freezing levels 800 m. Monday: Heavy snow expected 20-35 cm. Ridegtop winds strong from the southwest. Alpine temperatures near -1 and freezing levels 800 m. Tuesday: A mix of sun and cloud. Ridgetop wind light from the West. Freezing levels 800 m.
Avalanche Summary
On Saturday, the strong westerly winds were responsible for triggering a couple of wind slabs up to size 1.5 from north-easterly aspects in the alpine. On Friday and MIN reported a rider triggered wind slab avalanche size 1.5 from a southwesterly aspect. The person rode out of the avalanche and the crown was reportedly 35 cm deep. Friday also saw a natural cycle up to size 2.5 in the recent storm snow.
Snowpack Summary
Up to 30 cm of new snow overlies a plethora of old snow surfaces including the March 9th and 19th surface hoar existing on high northerly aspects and a melt-freeze crust basically on all aspects at treeline and below. The new storm snow will initially have a poor bond to these buried interfaces and lower elevation snow will likely become moist on Sunday. Strong easterly winds have redistributed the new snow onto leeward aspects forming thicker and likely more reactive slabs. Forecast weekend winds from the southwest will likely build new wind slabs on easterly aspects. Deeper in the mid-pack, layers of crusts, facets, and isolated surface hoar buried 50 to 100 cm exist from mid- and late-February and a surface hoar/ crust layer from January is buried around 150 to 200 cm. Near the bottom of the snowpack, sugary facets exist in colder and dryer parts of the region, such as the far north. These buried layers are currently dormant.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.