Avalanche Forecast

Issued: Apr 5th, 2018 3:57PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs, Persistent Slabs and Cornices.

pgoddard, Avalanche Canada

Sea To Sky.

Avalanche activity is possible on steep solar aspects if the sun peeks out.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Saturday

Weather Forecast

FRIDAY: Light snow. Moderate southerly winds. Freezing level near 1700 m.SATURDAY: Moderate snow. Light winds. Freezing level near 1800 m.SUNDAY: Light snow. Light winds. Freezing level near 1400 m.Click here for more information in the Mountain Weather Forecast.

Avalanche Summary

Skiers triggered two large persistent slabs on Wednesday. One was reported as a size 3, 50-200 cm deep. Several loose wet avalanches were observed on steep sunny slopes.

Snowpack Summary

Storm snow and wind are combining to create new slabs. Cornices are reported to be large and fragile. New snow will overlie various old surfaces including previous storm snow, melt freeze crusts on sunny aspects, scoured old hard wind slabs and dry snow.A weak layer consisting of surface hoar, facets or a sun crust buried in late March is now down about 60-80 cm. This is patchy in its distribution, but is still producing sporadic large avalanches. It is mostly likely to be problematic on shady aspects between 1900m and 2250m.The mid and lower snowpack are strong and well settled.

Problems

Storm Slabs

Recent snow and wind have formed slabs which could be triggered with the weight of a person.

Travel on ridgetops to avoid wind slabs on slopes below.Use conservative route selection: choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Persistent slabs are most likely to be triggered with a large load like cornice fall; or by a person in a thin or variable-depth snowpack spot.

Pay attention to overhead hazards like cornices which could trigger persistent slabs.Avoid steep convexities or areas with a thin or variable snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Cornices

Large fragile cornices are a hazard in themselves, but can also act as a trigger for large avalanches.

Avoid steep slopes below cornices.Give cornices a wide berth when travelling on ridges.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Apr 6th, 2018 2:00PM