Avalanche Forecast

Issued: Jan 3rd, 2018 4:01PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

Heads up to ice climbers and steep skiiers: the danger may be elevated in steep terrain and gully features, especially on solar aspects if the sun is out. Loose dry snow is sluffing fast and far and can knock you off or bury you in a terrain trap!

Summary

Weather Forecast

Alpine temps will be in the -5 to -10 range for the next three days. There may be some lingering cold air in the valley, so watch for the potential for an inversion, but the forecasts aren't calling for anything extreme. Winds will be generally light from the SW, increasing by the weekend. Friday and Saturday look to be overcast with light snow

Snowpack Summary

The surface snow is a mix of soft powder and wind effect in alpine areas. The recent cold temperatures have weakened the upper half of the snowpack, and several weak layers exist in the top 60 cm. The most reactive of these are thin hard windslabs in exposed alpine terrain. The loose surface snow will run far when even a small avalanche starts.

Avalanche Summary

Loose avalanches were running far on steep rocky solar terrain today. Warm temps and sun were the trigger, and these were generally small (up to size 1.5) but big enough to knock a climber off their feet or bury them in a terrain trap. A larger loose dry avalanche that wasn't solar triggered was reported on Heineken Hall ice climb

Confidence

Due to the number of field observations

Problems

Loose Dry

The cold temperatures have facetted the surface snow, and sluffs can pick up mass and travel far. Big sluffs are possible if you are climbing in gullies with steep terrain above, or skiing steep lines. Heads up on solar aspects in particular

The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.Avoid ice climbs exposed to steep rocky terrain on solar aspects during the middle of the day.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

Moderate winds on Jan. 1st created hard windslabs in exposed alpine areas. In places, these sit on a layer of facets from the christmas cold snap and were reactive to skiier traffic in the Lake Louise Backountry on Jan. 2nd.

Use caution in lee areas. Recent wind loading has created wind slabs.Watch for surface cracking and stiffer surface layers of snow. Avoid wind loaded terrain.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 4th, 2018 4:00PM