Avalanche Forecast

Issued: Apr 11th, 2018 5:02PM

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

jsmith, Avalanche Canada

Northwest Coastal.

Forecast new snow and wind Wednesday night are expected to create fresh storm slabs reactive to human triggers.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

TONIGHT: 5-15 cm new snow. Strong southeasterly ridgetop winds. Freezing level around 500 m.THURSDAY: Cloudy with flurries. Light southwesterly ridgetop winds. Freezing level around 1000 m.FRIDAY: 5-15 cm new snow. Strong southwesterly ridgetop winds. Freezing level around 1000 m.SATURDAY: 5-10 cm new snow. Moderate southwesterly ridgetop winds. Freezing level around 1000 m.

Avalanche Summary

Numerous natural loose wet avalanches on all aspects up to size 2 and several natural wind slabs on north aspects up to size 2.5 were reported near Bear Pass on Tuesday. Forecast snow and wind on Wednesday night are expected to create fresh storm slabs reactive to human triggers.

Snowpack Summary

Rain and warming to ridge top elevations have created wet or moist snow in the top 20-30 cm of the snowpack that is likely to be covered by 5-15 cm of new snow by Thursday morning. The new snow and strong southeasterly winds are expected to form fresh storm slabs reactive to human triggers. In the south of the region, two layers of surface hoar are buried approximately 70-100 cm deep. The layers are most prominent on north to east aspects and were buried early-March and mid-March. In the north of the region, these layers are around 40 cm deep.Bellow these March layers the mid-pack is generally well-settled and strong. However, shallower parts of the region, such as the far north, have weak sugary facets near the bottom of the snowpack.

Problems

Storm Slabs

New snow may bond poorly to an underlying crust. Watch for fresh storm slabs in leeward areas near ridge crests and convex features, as well as loose snow releases in steep terrain.

Use caution in lee areas in the alpine and treeline. Storm snow may form touchy slabs.Use small slopes with low or no consequence to test the bond of the new snow.Watch for signs of instability such as whumphing, cracking, or recent natural avalanching.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

Sun and daytime warming are factors to keep in mind. Watch for wet snow on sunny aspects and lower elevation slopes, especially in the afternoon.

Watch for signs that the snow is heating up such as pin-wheeling or the surface snow becoming moist.Avoid steep terrain that is in the sunshine.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Apr 12th, 2018 2:00PM