Regions
Northwest Coastal.
Expect to find lingering wind slabs at high elevations and wet snow at low elevations, especially if the sun comes out for any length of time.
Confidence
High - The weather pattern is stable
Weather Forecast
Not much change in the weather pattern: A mix of sun and increasing cloud and little if any precipitation until Tuesday.SUNDAY: Partly cloudy / Light northerly winds / Alpine temperature +1 C / Freezing level 1400 m.MONDAY: Cloudy with isolated flurries / Light to moderate north westerly winds / Alpine temperature near 0 degrees C / Freezing level 1200 m.TUESDAY: Scattered flurries (5-10 cm possible) / Moderate westerly winds / Alpine temperature near 0 degrees C / Freezing level 700 m.
Avalanche Summary
Over the past three days, several wet loose avalanches were observed at tree line and below, primarily on sunny aspects. Some of these stepped down to basal facets in northern parts of the region.On Friday, a remote-triggered size 2 persistent slab was reported near Stewart, running on an east facing rib feature near 1600m. The slab (30-120cm thick) failed on the mid January layer, with surface hoar 4-8mm reported.
Snowpack Summary
Recent warming has melted and refrozen the snow surface at higher elevations. Expect the snow surface to be wet or a melt-freeze crust on all aspects except for possibly high elevation north facing. Strong easterly to southerly winds have redistributed any available soft snow and produced variable surfaces at high elevations, including wind slabs in lee and cross-loaded features. This overlies a sun crust on solar aspects and 5 to 20 mm surface hoar on sheltered, shady aspects at all elevation bands.Beneath this, layers of crusts, facets, and isolated surface hoar buried 50 to 100 cm exist below the surface from mid- and late-February. A surface hoar and 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.
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.