Avalanche Forecast

Issued: Mar 3rd, 2014 8:08AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs, Loose Dry and Persistent Slabs.

ali haeri, Parks Canada

Glacier.

We are at the beginning of a sequence of storms which has buried our latest weak layer. Choose more conservative terrain these next few days and minimize your exposure to overhead hazards.

Summary

Weather Forecast

We are still under the influence of arctic air as a Pacific system collides with it further south. As the Pacific system makes it way to the interior moderate snow and warming temperatures can be expected today into tonight. We will be between systems for most of tomorrow with light snow until the evening when a more significant wave arrives.

Snowpack Summary

20cm of low density snow has buried a sun crust on south and west aspects and buried surface hoar will most likely be found in sheltered areas below tree line. In the alpine and treeline strong north and east winds from the last few days created wind slabs which also just got buried . The Jan 28/Feb 10 PWL is down 1-1.4m under a cohesive slab.

Avalanche Summary

Natural avalanches are starting to run within the highway corridor this morning with this new load. 2 east of the Rogers Pass summit, size 2.5 and 3.0 on a north aspect and one to the west on a south aspect size 1.5. All were steep gully features. Backcountry users can expect to see natural activity increase as it continues to snow.

Confidence

Problems

Storm Slabs

Soft slabs can be expected at higher elevations which is sitting over a weak layers of sun crust and facets. As winds and snow amounts increase this slab will tighten up and become more reactive.

Minimize exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Dry

Expect fast sluffing in steep terrain today capable of gaining mass. Exercise good group management such that people aren't riding below or above one another

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

The sun crust/surface hoar layer down 1-1.5m is still producing hard sudden results in snowpack tests. This indicates that the layer is difficult to trigger but will propagate widely if it does.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.Whumpfing is direct evidence of a buried instability.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Mar 4th, 2014 8:00AM