Avalanche Forecast

Issued: Mar 18th, 2017 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Loose Wet, Wind Slabs and Deep Persistent Slabs.

deryl kelly, Parks Canada

Jasper.

Check Alberta 511 for projected opening times and date for the Icefields Parkway (93N).

Summary

Weather Forecast

Snow forecast to taper off, tracking northward from the Icefields through Jasper over the evening. The likely HST total expected to be close to 20cm as the storm breaks. Scattered flurries and moderate to strong gusty SW winds to mark the exit of the snow. Scattered flurries and broken skies fx for Sunday. Cooler expected, high of -12 alpine temps.

Snowpack Summary

+50cm HST this month redistributed with Mod SW winds. Deeply loaded (100+ cm) lee areas with unpredictable spacial variability. Buried localized solar, rain and melt-freeze crusts, up to 2000+m on S and 1600m in the N asp. New snow weakly bridging a faceted older snow pack. Morphing interfaces scattered, at depth through the midpack to ground.

Avalanche Summary

Numerous large natural avalanches (class 3) were observed from the Maligne area to the icefelds at Tree Line and above. These slab avalanches are failing at varied depths; from recent storm snow to deeper older instabilities. Warm temperatures and precipitation will keep the landscape dangerously active.

Confidence

Problems

Loose Wet

Rain to treeline and warm temperatures will produce numerous avalanches of this type. Some of these will step down to ground producing full path releases.

Avoid all avalanche terrain.Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 3

Wind Slabs

40cm of storm snow over the week has formed a dangerous windslab. Wide crowns up to 2m deep have been seen from Maligne to Parkers area. Strong to extreme SW winds and warm temps will keep this layer very active.

It is a good time to stay within the boundaries of a ski resort.Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

2 - 3

Deep Persistent Slabs

The widespread observations of large and deep avalanches indicates strongly that many of these events are from this instability. Increased loading and warm temperatures will keep this layer active.

Be careful with low angle slopes that may not normally be a concern.Avoid all avalanche terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 4

Valid until: Mar 19th, 2017 4:00PM