Avalanche Forecast

Issued: Apr 12th, 2014 8:09AM

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

catherine brown, Parks Canada

Glacier.

Stronger solar inputs will increase avalanche hazard by the afternoon. Use safe spring travel techniques like traveling early in the day on sun effected terrain before the surface crust breaks down.

Summary

Weather Forecast

A mix of sun and cloud are forecast today with freezing levels rising to 1600 m. Light to moderate ridge top winds from the north should keep upper elevations cooler. No precipitation is forecast until Tuesday, as Sunday and Monday remain sunny with a weak temperature inversion in place.

Snowpack Summary

Spring time conditions exists with a surface crust on all but due north aspects above 2000m. Lower temps last night resulted in a good freeze, with valley bottom crusts will break down quickly today. On solar aspects crusts in the upper 50cm are failing in the moderate range in stability tests. The mid to lower snowpack is very well settled.

Avalanche Summary

Yesterday at midday a small avalanche cycle occurred during a period of intense precipitation. We observed loose wet avalanches up to size 2.0 on solar aspects and two persistent slab releases up to size 3.0. On Thursday night, we observed an impressive glide crack release on a south aspect east of Rogers Pass that produced a size 3.0 avalanche.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Loose Wet

Warm temperatures and solar inputs will deteriorate snow stability today as avalanche hazard rises in the afternoon. Watch for terrain above you getting headed through out the day and use safe travel techniques to manage your group.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Start and finish early before the surface crusts melt.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

New snow in the past weak is possible to skier-trigger. Watch for hard, wind-deposited snow on lee features in the alpine. Storm slabs failing on crusts is possible at lower elevations.

Use caution in lee areas. Recent wind loading have created wind slabs.If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Weak layers buried deeply in the snowpack are still releasing naturally and producing avalanches up to size 3.5. Warm temperatures and solar inputs elevate this hazard. Large, heavy triggers like cornice falls could trigger a large avalanche.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Pay attention to overhead hazards like cornices.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Apr 13th, 2014 8:00AM