Avalanche Forecast

Issued: Feb 20th, 2014 4:00PM

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

mike eder, Parks Canada

Jasper.

Pay attention to changes in the snow as you approach treeline and travel through the lower alpine where terrain features have slabs on their lee aspect.

Summary

Weather Forecast

Light snow flurries may sporadically spread 5 - 10cm over the forecast area overnight. Cloudy skies and occasional flurries will continue through the weekend with a clearing trend beginning on Monday. This could arrive earlier or stall for a few extra days of clouds.

Snowpack Summary

Light snow flurries overnight did not add much load to the snowpack. There is about 30cm overtop of the Feb 10 interface which has surface facets and surface hoar from the previous cold weather. This seems to be most prevalent from treeline into the lower alpine elevations. Below tree line there is a supportive yet shallow mid-pack over facets.

Avalanche Summary

No new natural avalanches were observed in the icefields area today. Wednesday's patrol in the Maligne area produced a size 2 slab that was :35m wide, 60m long, on a NE aspect 38 degree slope just above treeline on the Feb 10 surface hoar/facet layer. Stability tests showed moderate sudden planar/sudden collapse on this layer.

Confidence

Problems

Persistent Slabs

This persistent weak layer consists of facets and surface hoar that were covered. It sits on a mixture of crusts and firm supportive snow. This seems to be of most concern at the Treeline and lower alpine elevations between 2000m and 2400m.

Caution around convexities or areas with a thin or variable snowpack.Assess start zones carefully and use safe travel techniques.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Wind Slabs

Lee aspects of ridgetops and terrain features should be carefully evaluated for windslabs.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 21st, 2014 4:00PM