Avalanche Forecast

Issued: Mar 20th, 2016 8:31AM

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

Avalanche Canada jlammers, Avalanche Canada

Forecast snowfall amounts vary greatly across the region with areas to the far south and west expecting the highest accumulations. Pay close attention to how much snow falls in your area, and be prepared to back off to simple terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Monday

Weather Forecast

In most areas 10-15cm of snow is expected to fall between Sunday night and Monday afternoon, although more than double that amount may fall in the far south and western parts of the region. Generally overcast skies and light flurries are forecast for Tuesday and Wednesday. Ridgetop winds will be moderate to strong from the southwest on Sunday night and Monday, and then become light on Tuesday and Wednesday. Freezing levels will hover around 1400m on Monday and Tuesday, and then drop to about 1200m by Wednesday.

Avalanche Summary

On Friday, there was an anomalous size 2.5 slab avalanche on an unsupported rocky face on the northwest corner of Mt Fissile (in the Fitzsimmons Range) at about 1900m. Although the sliding layer is unknown, the avalanche was thought to have been triggered by warming. There have also been numerous reports of solar-triggered cornice falls. Some cornice falls have been large (up to size 3), but most have only entrained surface snow. New snow and wind on Sunday and Monday will create new wind slabs at higher elevations while rain will promote a round of loose wet avalanche activity below treeline.

Snowpack Summary

New snow and moderate winds on Sunday and Monday will form new wind slabs at higher elevations. Below treeline, rain will saturate the upper snowpack. The new snow will overlie a sun crust on sun-exposed slopes, dry settled powder on shady slopes, and pockets of fresh wind slab in lee and cross-loaded terrain near ridge crests. Below the new snow the snowpack is strong and well-settled throughout with no notable persistent weaknesses. Cornices are reported to be large and fragile.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and southwest winds will form new wind slabs at treeline and above. New wind slabs will be most reactive at higher elevations where temperatures have remained colder.
Be cautious as you transition into wind affected terrain.>Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Cornices

An icon showing Cornices
Cornices are huge and potentially weak. New wind and snow will encourage ongoing cornice development.
Give cornices a wide berth when travelling on or below ridges.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Mar 21st, 2016 2:00PM

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