Avalanche Forecast

Issued: Apr 3rd, 2015 9:33AM

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

Avalanche Canada bcorrigan, Avalanche Canada

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Summary

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

15 to 20cm of precipitation on Friday afternoon into Saturday, before generally dry conditions prevail for Sunday. Mostly light and gusty south easterly alpine winds are expected throughout the forecast period. Daytime high freezing levels should hover around 1400 m each day.

Avalanche Summary

Reports from Wednesday are limited to just one new Size 2 natural wind slab avalanche on a northeast facing alpine slope below a ridge crest. However, reports from Tuesday include several small natural and skier triggered wind slab avalanches in lee and cross-loaded treeline and alpine terrain. The reports mentioned surprisingly little large avalanche activity given the strong winds and amount of fresh snow available for wind-transport.

Snowpack Summary

Approximately 15-30 cm of dense storm snow overlies a variety of crusty old surfaces. Recent strong winds have scoured windward slopes and loaded leeward slopes below ridge crests and behind terrain features. Persistent weaknesses buried in the upper snowpack may include hard crusts and/or facet crystals, although not much is known about the reactivity or spatial distribution of these layers. At the base of the snowpack, weak facets may be found. Cornices are large and potentially fragile. Unpredictable, full-depth glide avalanches are also a concern on low elevation slopes with smooth ground cover (grassy slopes, rock slabs, etc.) where large cracks have formed from the snowpack slipping on the ground.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent snow profile data shows numerous crusts and faceted crust layers buried in the top 50cm of the snowpack. The last few storm cycles have added light wind slabs to the scenario. Watch for wind loading on north, northeast and northwest slopes.
Minimize overhead exposure; avalanches triggered by windloading may reach run out zones.>Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Apr 4th, 2015 2:00PM