Avalanche Forecast

Issued: Mar 7th, 2018 4:11PM

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

pgoddard, Avalanche Canada

North Columbia.

Give cornices a respectful berth.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

THURSDAY: Cloudy. Around 10-15 cm snow. Treeline temperature near -5. Light winds.FRIDAY: Mix of sun and cloud. Treeline temperature near -3. Light winds.SATURDAY: Mainly sunny. Treeline temperature near -1. Light winds.

Avalanche Summary

On Tuesday, a few small loose and slab avalanches were reported.A few large (size 2-3) persistent slabs also failed early this week, both naturally and with a remote trigger. These were reported as failing on the February persistent weak layers on south to west aspects, mostly in the east of the region.

Snowpack Summary

Solar aspects have developed new sun crusts which new snow may sluff easily on. Recent storm snow continues to settle. A couple of layers buried in mid-late February (down around 50-100 cm) are variably reactive, but both have the potential to create surprisingly large avalanches if triggered. Initially, this interface was most reactive on solar aspects, where it presents as a buried sun crust. However, it has been triggered on shady aspects too, where surface hoar and/or facets exist.Deeper persistent weak layers from January and December are generally considered dormant, but could wake up with forecast warming, a surface avalanche stepping down, cornice fall, or a human trigger in a shallow or variable-depth snowpack area. These layers consist of sun crust, surface hoar and/or facets. Facets linger at the base of the snowpack.

Problems

Wind Slabs

New snow and wind may build new wind slabs. Stay well away from large looming cornices.

Extra caution needed around cornices with current conditions.Use ridges or ribs to avoid pockets of wind loaded snow.

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

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 convoluted terrain with variable or shallow snow depths and multiple trigger points.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Mar 8th, 2018 2:00PM