Avalanche Forecast

Issued: Feb 18th, 2014 8:01AM

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

ali haeri, Parks Canada

Glacier.

Our weak layers are at a dangerous depth. A deeper more cohesive slab means rider triggering will taper off but consequences will increase. These conditions are unlikely to change in the near future.

Summary

Weather Forecast

There's a break between storms until late this afternoon when a Pacific system arrives to the Interior. Light to moderate snowfall amounts are forecast into tonight with strong southwest winds. This system will pass by early Wednesday morning leaving us with a north westerly flow with lingering flurries and light snow until Thursday.

Snowpack Summary

100 to 140cm of recent storm snow, deeper amounts west side of the summit, is settling over the Feb 10 facet/surface hoar/crust interface which depends on aspect and elevation. 10cm below is the Jan 28 surface hoar layer. The Jan 22 surface hoar layer is evident 5cm deeper. Test results were easy to moderate and sudden planar on the Jan 28 layer.

Avalanche Summary

We had a natural avalanche cycle yesterday morning producing 5 size 3.0 slab avalanches east of the Rogers Pass summit and 1 size 3.5 to the west. Numerous size 2.0 to 2.5 avalanches were also observed within the highway corridor.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Problems

Storm Slabs

As the slab over the weak layers down 100-140cm becomes more cohesive, it changes in how it reacts to a riders weight. The highly reactive stage may have passed but it is at a depth where triggering will be less frequent but much more dangerous.

Remote triggering is a concern, watch out for adjacent slopes.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

We had strong winds yesterday morning and there's a concern the associated instabilities still exist up high.

Be cautious as you transition into wind affected terrain.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Feb 19th, 2014 8:00AM