Avalanche Forecast

Issued: Apr 5th, 2017 8:00AM

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

percy woods, Parks Canada

Glacier.

Pay attention to overhead hazards such as cornices which may trigger persistent weak layers resulting in large avalanches.

Summary

Weather Forecast

Mainly cloudy today wit ha chance of some sunny breaks. Alpine temps should warm to -1C with moderate south winds maintaining a cooler surface. Freezing levels are expected to be up to 2000m today. Precipitation in the form of snow at higher elevations is expected to begin tonight and continue through the weekend. Total accumulations of 30cm.

Snowpack Summary

20-30cm of storm snow from last weekend is forming soft slab in the immediate lee of ridges in the alpine. Field tests from earlier in the week were producing resistant planar results in the top 60cm. Solar aspects have a temperature crust up into the alpine. Protected N'ly aspects have good quality powder skiing, sluff management may be required.

Avalanche Summary

One size 3 natural cornice triggered slide in Crossover path yesterday in the highway corridor. Two other smaller slides were observed on solar aspects along the highway. Field team skied steeper N'ly aspects off of Glacier Crest and the Ravens. Both locations resulted in 0.5 surface sluffs from initial turns on the slopes.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

SW winds continue to redistribute snow onto alpine lee slopes forming soft slab. Look for soft slab in the immediate lee of ridges and crossloaded features. Light surface wind effect is widespread above treeline.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Avoid steep convexities or areas with a thin or variable snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

Cornices are large and are failing sporadically and almost daily. These large triggers are capable of triggering persistent weak layers resulting in large slides.

Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.Avoid travel on slopes that are exposed to cornices overhead.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 6th, 2017 8:00AM