Regions
South Coast Inland.
Snow and wind at upper elevations Monday night is expected to build fresh wind slabs.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Tuesday
Weather Forecast
MONDAY Night: Wet snow, accumulation 5-15 cm at upper elevations / moderate to strong southwest wind / alpine temperature -3 C / freezing level 1500 m dropping to 1000 mTUESDAY: A mix of sun and cloud with isolated wet flurries / moderate southwest wind / alpine temperature -2 C / freezing level 1400 m WEDNESDAY: Mix of sun and cloud / light east wind / alpine temperature 5 C / freezing level 1800 mTHURSDAY: Mix of sun and cloud / light east wind / alpine temperature 4 C / freezing level 1800 m
Avalanche Summary
No recent avalanche activity has been reported. In the far north of the region on Friday and Saturday loose wet avalanche activity up to size 2 was reported on solar aspects. Sporadic natural slab avalanches were also reported in the alpine and treeline, but no activity was reported from north aspects.
Snowpack Summary
Up to 15 cm of new snow at upper elevations Tuesday night sits on a variety of surfaces. On higher north aspects above 2000 m it may sit on some dry, faceted snow and/or isolated old wind slabs. Most other places the new snow is sitting on either moist snow or a crust. There are still a handful of melt/freeze crusts, surface hoar and facets in the upper snowpack including the February facet interface which is down 20 to 60 cm below the surface, but all of these layers appear to have gone dormant for the time being. The snowpack at mid and upper elevations is expected to continue to gain strength as we enter a period of consecutive nights with below freezing temperatures.
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.