Avalanche Forecast

Issued: Feb 26th, 2013 8:15AM

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

Ali Haeri, Parks Canada

Glacier.

Summary

Weather Forecast

Weak ridge of high pressure will bring cooler temperatures and keep things dry today with some sunny breaks. Next system pushing into the interior tomorrow only bringing light precipitation until Thursday evening when a more significant system arrives.

Snowpack Summary

Top 30 cm settling storm snow. Feb 12 surface hoar and crust layers down 40-55 cm, fist to 1 finger snow over top. Mid pack is well settled.

Avalanche Summary

Avalanche control yesterday west of Rogers Pass summit produced 4 size 3.0 avalanches and 4 size 2.0-2.5.7 natural avalanches size 1.5-2.5 east of the summit.From Feb 24: Skier remote size 2.0, from 30m. 2010m, north aspect, 35-40 degrees. 42 cm deep, 100m X 100m on Feb 12 surface hoar size 3-8

Confidence

Due to the quality of field observations on Tuesday

Problems

Persistent Slabs

Surface hoar layer buried 40-55cm. This layer is reactive to rider triggering and remote triggering. The overlying slab will continue to produce avalanches with larger propagation and more consequence for the foreseeable future.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

Instabilities in the upper 50cm from the recent storm snow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Solar radiation from forecast sunny breaks may trigger loose avalanches. Caution below rocky outcroppings and watch the overhead cornice hazard. With enough mass these may trigger the deeper instability.

Pay attention to overhead hazards like cornices.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 27th, 2013 8:00AM