Regions
Northwest Inland.
The coastal storm won't bring much new snow, but strong winds will maintain touchy conditions on Monday. Keep seeking out supported lines in sheltered areas while the storm snow settles and bonds.
Weather Forecast
Monday: Cloudy with scattered flurries bringing 4-8 cm of new snow, continuing overnight. Moderate to strong southwest winds, increasing over the day. Freezing level to 1100 metres with alpine high temperatures around -3.Tuesday: Mainly cloudy with continuing isolated flurries and a trace of new snow. Strong west winds. Freezing level to 1000 metres with alpine high temperatures around -5.Wednesday: A mix of sun and cloud. Moderate to strong west winds. Freezing level to 1000 metres with alpine high temperatures around -6.
Avalanche Summary
On Saturday, ski cutting on convex rolls below treeline produced size 1.5 slabs in the recent storm snow down 30 cm deep. These failed over the widespread melt-freeze crust and gathered substantial mass as they traveled downslope.
Snowpack Summary
Up to 40 cm of new storm 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. 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.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.