Avalanche Forecast

Issued: Mar 30th, 2017 4:22PM

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

Avalanche Canada mbender, Avalanche Canada

The weather forecast calls for a short period of more settled weather

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

FRIDAY: Mix of sun and cloud / Light southwest wind / Alpine temperature -2 / Freezing level 1300mSATURDAY: Flurries, accumulation 5cm / Moderate southwest wind / Alpine temperature -2 / Freezing level 1300mSUNDAY: Mix of sun and cloud / Light to moderate west wind / Alpine temperature -1 / Freezing level 1200m

Avalanche Summary

A report from Tuesday indicated a natural size 2 cornice failure that was suspected to be triggered by warming temperatures at tree line on a west aspect. Additionally, on Tuesday and Wednesday several explosive and skier controlled avalanches to size 2 and 2.5 were reported from a variety of aspects. These were mostly wind and storm slabs failing 10-40cm deep. Some were also triggered by cornices pulling out 20-40cm slabs on slopes below.

Snowpack Summary

A series of snowfalls over the early part of the week accumulated 30-60cm of storm snow that has been redistributed by predominantly southwest and southeast winds. 2000m and below, the storm snow lies above a crust that formed last week. A rain crust that was buried mid March is now 90-120 cm deep. The mid-February crust/facet layer can still be found at the upper end of tree line and into the alpine. This layer is generally 120-170 cm deep but may be present nearer to the surface in wind scoured areas. Although there is growing confidence that this layer seems to be becoming dormant, a storm slab or cornice release in the right location may have the potential to trigger any of the deeply buried weak layers.

Problems

Storm Slabs

An icon showing Storm Slabs
New storm slabs are expected to continue to be reactive as the sun comes out on Thursday. The new snow could present as loose wet avalanches at lower elevations or on steep sun exposed slopes at upper elevations.
Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Be cautious as you transition into wind affected terrain.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Cornices

An icon showing Cornices
With recent warm temperatures, snow and wind cornices have grown large and overhanging. While cornices are a hazard in themselves, the danger increases when they have the potential to act as a trigger to slabs sitting beneath them.
Give cornices a wide berth when traveling on ridgesAvoid exposure to slopes that have cornices overheadEven small cornice falls may trigger larger avalanches.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 31st, 2017 2:00PM

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