Avalanche Forecast

Issued: Apr 9th, 2017 5:37PM

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

Avalanche Canada mgrist, Avalanche Canada

Cornices and wind slabs are the primary concern. Solar radiation is a common cornice trigger. Limit your exposure when it's cloudy and completely avoid cornices when it's sunny.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

We're looking at mostly unsettled weather throughout the forecast period, with a brief respite on Tuesday. MONDAY: Mix of sun and cloud with isolated flurries (2-5cm). Moderate southwest ridgetop winds. Freezing level around 1700 m.TUESDAY: Cloudy with sunny periods. Light southerly ridgetop winds. Freezing level around 1800 m.WEDNESDAY: Flurries (5-10cm). Moderate easterly ridgetop winds. Freezing level around 1600 m.

Avalanche Summary

On Sunday, several small (Size 1 or less) loose dry and storm slab avalanches were reported running on the firm melt-freeze crust from Friday-Saturday.

Snowpack Summary

On Saturday into Sunday, 5-15cm of new snow fell above treeline with southerly winds. Small wind slabs have formed in lee features below alpine ridgetops. The new snow fell on a firm crust up to 2100m (on north aspects) and 2400m (on south aspects), and may slide easily on this layer.  Cornices remain large, looming, and are best avoided. The snowpack is well settled and continues to transition into a spring snowpack, becoming isothermal at treeline in some areas and below treeline in most areas. The bottom third of the snowpack is composed of weak facets, but this deep persistent weakness has not been reactive for several weeks. That said, a large trigger like a cornice, or rapid warming of the snowpack could potentially trigger this layer.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and moderate southwest winds have formed thin wind slabs below alpine ridgetops.
Use ridges or ribs to avoid pockets of wind loaded snow.Be alert to conditions that change with elevation.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices
Solar radiation is a common cornice trigger. Limit your exposure when it's cloudy and completely avoid cornices when it's sunny.
Minimize exposure to overhead hazard from cornices.Give cornices a wide berth when travelling on or below ridges.Cornices become weak with daytime heating, so travel early on exposed slopes.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 10th, 2017 2:00PM