Avalanche Forecast

Issued: Feb 1st, 2015 8:02AM

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

ali haeri, Parks Canada

Glacier.

Avalanche hazard will steadily rise as snow load increases over newly buried surface hoar and crust layers.

Summary

Weather Forecast

Low pressure system will arrive to the Interior this morning bringing light to moderate amounts of snow with rising freezing levels to ~1000m. Treeline winds are forecast to stay light for most of the day and will pick up tonight. This unsettled pattern will continue for the next few days with a series of fronts that will pass through our region.

Snowpack Summary

Up to 20 cm of snow overlies the Jan 30 crust which can be found up to 2200m. Surface hoar was found on the crust and facetting has been occurring underneath it. Above 2200m firm wind pressed snow is found 20cm down. The Jan 15 surface hoar layer is down 60-90cm. The Dec 17 surface hoar/ crust complex is down 130-180cm.

Avalanche Summary

Yesterday, there was a report of a human triggered avalanche, size 1.5 at Bruins Pass into 8812 Bowl off the east ridge of 8812 Peak ~2700m, SE aspect, 15-20cm deep. Along the highway corridor there were was one loose natural avalanche size 1.5 east of the Rogers Pass summit.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

~20cm of recent snow over a firm surface may be reactive to riders where wind has firmed it up enough to create a soft slab. Areas to watch for this are near ridge crests or cross loaded terrain features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The mid January surface hoar layer is buried 60-100cm deep. Getting this layer to fail will be difficult but triggering it from shallow areas or from heavy loads such as a cornice fall remains possible.

Pay attention to overhead hazards like cornices.Avoid convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Feb 2nd, 2015 8:00AM