Avalanche Forecast

Issued: Dec 30th, 2015 8:00AM

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

danyelle magnan, Parks Canada

Glacier.

We are in for some beautiful days with great snow, but sunshine and powder aren't always the best combination. Be cautious on steep, solar aspects where the power of the sun may trigger avalanches.

Summary

Weather Forecast

We are in for a prolonged dry spell due to a high pressure system. Today expect temps ranging from -18 t0 -8 with light to moderate N'ly winds at ridgetop. Most of Rogers Pass should be above the valley cloud and get plenty of sun. Temps will gradually warm over the next few days, with an inversion and above freezing temps expected by Friday.

Snowpack Summary

Cold temps are slowing the settlement of last weeks snow and causing surface facetting which is helping to keep the surface snow soft. 30-40cm of lower density snow sits on a well settled mid pack. Moderate S'ly winds over the weekend shifted to N'ly yesterday, windloading the immediate lee of alpine features and creating areas of thin wind-slab.

Avalanche Summary

Yesterday there were numerous loose, solar triggered avalanches. They were up to size 1.5 and were occurring from steep, rocky terrain exposed to the sun. On Monday, a skier accidentally triggered a size 1.5 avalanche on a W aspect at ~2200m while descending "NRC" on the Macdonald West Shoulder. There have also been glide crack releases observed.

Confidence

Problems

Loose Dry

The sun sure feels good but it also packs a punch into the snowpack. Expect solar triggered avalanches from steep solar aspects, especially if there are exposed rocks and cliffs baking in the sun. Expect sluffing from steep slopes on your descent.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Thin windslabs exist in immediate lee of some alpine features. Keep them in mind if you venture into more aggressive terrain where getting pushed around by a small slide could have serious consequences.

Use ridges or ribs to avoid pockets of wind loaded snow.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 31st, 2015 8:00AM