Avalanche Forecast

Issued: Mar 15th, 2017 4:27PM

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

Avalanche Canada triley, Avalanche Canada

Stormy weather continues to bring new snow, rain, and wind. Freezing levels are tricky to forecast, and overnight re-freeze are not certain.

Summary

Confidence

Moderate - Freezing levels are uncertain on Thursday

Weather Forecast

Overnight: Freezing level at 2200 metres, slowly dropping by morning to 1500 metres. Expect 5-10 mm of precipitation that will mostly be rain, except at the highest elevations, combined with strong southwest winds. Thursday: Daytime freezing level around 1500 metres, 3-5 cm of new snow in the alpine, and moderate westerly winds. Friday: Overnight freezing down to valley bottoms, and then rising up to at least 2200 metres. Mostly sunny with light southwest winds. Saturday: Freezing level remaining above 2000 metres, 5-10 mm of precipitation, combined with strong southwest winds.

Avalanche Summary

Wind slabs are expected to continue to develop in the alpine above the high freezing levels. At lower elevations, snow may be moist or wet and release easily in pockets of loose wet snow. The possibility of deep persistent avalanches continues during this period of warm and stormy weather. No new reports of avalanches.

Snowpack Summary

A warm, wet, and windy storm will form fresh wind slabs at higher elevations while rain will fall below treeline. March has delivered regular storms with roughly 50-90 cm of snow sitting above crust and facet interfaces from February. In some areas the snow above these interfaces may have a poor bond. The mid-pack in this region is generally strong, but the bottom third of the snowpack is composed of weak sugary facets roughly 1-1.5 metres deep. This remains a concern and should be on your radar, especially with the recent loading and ongoing warming.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs are expected to continue to develop due to the forecast new snow and wind.
Use conservative route selection, choose moderate angled and supported terrain with low consequence.Be alert to conditions that change with elevation and time of day.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Storm loading and warming may increase the likelihood of triggering large deep persistent slab avalanches. Cornice falls may trigger deep persistent weak layers.
Avoid steep convexities or areas with a thin or variable snowpack.Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 16th, 2017 2:00PM