Avalanche Forecast

Issued: Apr 1st, 2017 3:45PM

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

Avalanche Canada triley, Avalanche Canada

New snow and wind are expected to develop new wind slabs in the alpine and at treeline on Sunday.

Summary

Confidence

High -

Weather Forecast

Overnight: 3-5 cm of new snow with moderate northwest winds and freezing down to valley bottoms. Sunday: Mix of sun and cloud with moderate northwest winds and daytime freezing level up to 800 metres. Monday: Overnight re-freeze down to valley bottoms followed by mostly sunny skies and light winds. Tuesday: Mix of sun and cloud with increasing southerly winds.

Avalanche Summary

A natural cornice fall released a wind slab or perhaps a persistent slab on a northeast aspect that was size 2.5; this was reported from the Microwave on Thursday but may have occurred on Wednesday. You can see the full MIN report here. Storm slabs up to size 2.5 were reported from the western extent of the region in the Howson's, where the snowpack is more like the Northwest Coastal region. No new avalanches reported from the rest of the region.

Snowpack Summary

Light snow combined with moderate southwest winds has developed wind slabs in the alpine and in some exposed treeline locations. Periods of sun and high daytime freezing levels have developed crusts below treeline and on sun exposed terrain at all elevations. The snow may be moist or wet below treeline during the warmest part of the day. The Mid-February crust and facet layer was reported to be down 75-90 cm in the Houston Telkwas sled area on Wednesday. The deep persistent weak layer of facets and/or a crust that were buried early in the winter are still lingering near the bottom of the snowpack. This MIN report found the deep weak layer strengthening in the Telkwas.

Problems

Wind Slabs

An icon showing Wind Slabs
Expect new wind slabs to develop due to the forecast new snow and wind. Cornices are also expected to develop new growth, that may be weak and fall off naturally.
Be careful with wind loaded pockets. Be aware of wide variation in snowpack depthUse caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
A weak layer of facets and/or a crust that developed early in the winter lies near the bottom of the snowpack. Any change in the weather may affect the likelihood of triggering this deep weak layer.
Choose well supported terrain without convexities.Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Apr 2nd, 2017 2:00PM

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