Avalanche Forecast

Issued: Mar 13th, 2018 4:09PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

mconlan, Avalanche Canada

Northwest Coastal.

Strong winds have produced wind slabs in lee and cross-loaded features. The best riding will be in areas sheltered from the wind and effects from the recent warming.

Summary

Confidence

Moderate -

Weather Forecast

WEDNESDAY: Cloudy with light snowfall early morning, accumulation 2 to 5 cm, moderate southerly winds, alpine temperature -2 C, freezing level 1100 m.THURSDAY: Mostly cloudy with light snowfall, accumulation 1 to 3 cm, light northwesterly winds, alpine temperature -3 C, freezing level 900 m.FRIDAY: Mix of sun and cloud, light northwesterly winds, alpine temperature 0 C, freezing level 1500 m.

Avalanche Summary

Numerous wind slabs were triggered by skiers in immediate lee features. They were small (up to size 1.5) and generally on northerly aspects. Otherwise, widespread loose wet avalanche activity was noted in the region on southerly aspects, up to size 2.

Snowpack Summary

Strong easterly to southerly winds have redistributed recent snow and produced variable surfaces in alpine and treeline terrain, 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. Expect the snow surface to be a melt-freeze crust on solar aspects and on all aspects below 1400 m, up to 20 cm thick.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

Strong south to easterly winds have produced wind slabs in lee and cross-loaded terrain features. These slabs overly a crust or weak surface hoar layer in parts of the region, allowing for wide propagation and fast-moving avalanches.

Approach lee and cross-loaded slopes with caution.Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.Use caution above cliffs and terrain traps where small avalanches may have severe consequences.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Mar 14th, 2018 2:00PM