Avalanche Forecast

Issued: Jan 11th, 2019 8:03AM

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

percy woods, Parks Canada

Glacier.

Watch for an increasing avalanche danger this weekend with forecast freezing levels rising above mountain top.

Summary

Weather Forecast

Mainly cloudy today with light winds and an alpine high of -4C. The freezing level should rise to 1200m later today and is forecast to rise to 2900m for the weekend with an alpine high up to +5C forecast for Sunday. Watch for an increasing avalanche danger.

Snowpack Summary

Nearly 50cm of snow has fallen in the past 5 days. On southerly aspects, NE winds yesterday will have reverse loaded lees creating deeper pockets of soft slab. In exposed alpine areas and a ridge crest it will have buried old windslabs. The Jan 2 freezing rain crust is down ~90cm. The Nov 21st interface is now 1-2m in deep

Avalanche Summary

Yesterday skier remote triggered size 1 avalanche at 2100m on Puff Daddy from 10m distance, skier triggered slide in the Christmas Trees size 1, skier remote triggered size 1 slide 1700m up NRC. 20 avalanches observed in the highway corridor mostly in the size 2-2.5 range. Wed, skier accidental size 3.5 from the top of Camp West avalanche path.

Confidence

Freezing levels are uncertain

Problems

Storm Slabs

Recent snowfall combined with mild temps, has created soft storm slabs in many areas. Storm slabs have been reactive and easily triggered by skiers. Be especially cautious in alpine areas, where it has buried windslabs.

Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

The recent size 3.5 skier triggered aval in Camp West path highlights that in some areas persistent slabs may be reactive. The problem likely woke up with rapid wind loading and significant new snow in January and was triggerable in a shallow area.

Avoid steep convexities or areas with a thin or variable snowpack.Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2.5 - 4

Valid until: Jan 12th, 2019 8:00AM