Avalanche Forecast

Issued: Nov 28th, 2015 4:00PM

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

tim haggarty, Parks Canada

Banff Yoho Kootenay.

Despite the fact that a well settled snowpack exists in most areas there are still some tricks out there. Be aware of what the inversion may be doing to the terrain above you and remember that windslabs may still release in isolated areas. TH

Summary

Weather Forecast

Clear conditions with light winds and very warm alpine temperatures are forecast for Sunday and Monday with alpine temperatures remaining near freezing in the evenings. In sheltered sunny locations temperatures will return to well above freezing during the middle of the day. A temperature inversion will keep the valley bottoms cool.

Snowpack Summary

Strong temperature inversions have allowed sun crust formation on solar aspects TL and above while faceting continues TL and below. Expect to find widespread and variable windslabs in open areas at tree line and above. Isolated wind slabs that overly the typical Rockies facets can still be expected in thin areas.

Avalanche Summary

Some small solar triggered sluffs to size 1 observed on Friday. One older size 3 natural avalanche was also observed on the White Pyramid Glacier. This appears to have slid during the last major wind event a few days ago. In places it stepped down to glacier ice showing that on high North aspects there can be a basal weak layer to keep in mind.

Confidence

Problems

Loose Wet

With alpine temperatures only dropping a little below freezing overnight, we expect still expect solar triggered sluffing on Sunday.

Avoid ice climbs exposed to steep rocky terrain on solar aspects during the middle of the day.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

Small wind slabs are possible in isolated locations, perhaps providing a surprise during otherwise good conditions. The main concern is for terrain traps (above cliffs, gullies) where small avalanches have bigger consequences.

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

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Nov 29th, 2015 4:00PM