Avalanche Forecast

Issued: Mar 12th, 2018 4:21PM

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

mconlan, Avalanche Canada

Northwest Coastal.

Sustained winds have produced wind slabs in lee features. High freezing levels and sunny skies are warming the snowpack. The best riding will be in areas sheltered from the wind effect and sun, without any overhead exposure.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

TUESDAY: Mix of sun and cloud, light to moderate southeasterly winds, alpine temperature 3 C, freezing level 2500 m.WEDNESDAY: Cloudy with light snowfall, accumulation 2 to 5 cm, light southerly winds, alpine temperature 0 C, freezing level 1400 m.THURSDAY:Â Mix of sun and cloud, light northerly winds, alpine temperature -1 C, freezing level 1000 m.

Avalanche Summary

The recent snow was reactive on Sunday, producing storm and wind slabs in steep features.Â These avalanches have generally been small to large (size 1 to 2.5) and often in lee features.Â Loose wet avalanches have also been noted from natural and skier activity up to size 1.5.

Snowpack Summary

Sustained southerly winds have redistributed the 20 cm of recent snow and produced wind slabs in lee features.Â This overlies a sun crust on solar aspects and 5 to 20 mm surface hoar on sheltered, shady aspects at all elevation bands.Â Expect to find moist snow on solar aspects and on all aspects below 1300 m.Beneath this, expect layers of crusts, facets, and isolated surface hoar buried 50 to 100 cm below the surface from mid- and late-February.Â 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 southerly winds have redistributed the recent storm snow and formed touchy wind slabs in lee features. These slabs overly a weak surface hoar layer in parts of the region, allowing for wide propagation and fast-moving avalanches.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Loose Wet

High freezing levels and sunny skies are warming the snowpack, particularly on solar aspects. Pay close attention to the effects of the sun on avalanche terrain and avoid overhead exposure.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Mar 13th, 2018 2:00PM