Avalanche Forecast

Issued: Apr 25th, 2017 8:00AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs, Loose Wet and Cornices.

percy woods, Parks Canada

Glacier.

Tune in to solar radiation and daytime warming and their effect on snow stability.

Summary

Weather Forecast

A mix of sun and cloud today with no precipitation forecast. Alpine temperatures should reach a high of -4C with light SW winds. The freezing level should rise to 1600m. A cool, unstable air mass is the name of the game for the next few days.

Snowpack Summary

High elevation N'ly aspects above 2400m remain wintery, with winter stability issues. Warm temps and solar radiation have resulted in moist surface snow with the upper snowpack being a series of crust layers. Below treeline expect the snowpack to be isothermal. We are moving slowly into a spring melt freeze cycle.

Avalanche Summary

Several natural avalanches in the hwy corridor observed yesterday with the largest being a size 3 slide on Avalanche crest. Skiers have recently triggered soft slabs on high elevation N aspects. Sunday skiers triggered a size 2 slab on Cheops N5 at 2250m, it was 20cm deep and ran 300m. Shooting cracks caused a group to turn around on Ursus Major.

Confidence

Problems

Wind Slabs

Watch for fresh windslab on high elevation N aspects. Skiers reported triggering windslab to size 2 on alpine lee features on Sunday.

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

The melt freeze cycle is becoming established. Surface crusts break down with daytime warming and solar radiation. Avalanches start small but pick up mass where the snowpack is weak and isothermal.

Use extra caution on solar slopes or if the snow is moist or wet.Travel early before the heat of the day, and avoid big slopes.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Large cornices hang over alpine lee slopes. Strong solar and daytime warming may weaken these features promoting failure. Cornices are a large trigger and may wake deep persistent weak layers.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Pay attention to overhead hazards like cornices which could trigger slabs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 26th, 2017 8:00AM