Avalanche Forecast

Issued: Dec 24th, 2017 4:36PM

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

conrad janzen, Parks Canada

Banff Yoho Kootenay.

The avalanche hazard has been slowly decreasing but continue to watch for small avalanches in steep terrain, especially where there has been previous wind effect. Sluffing is also becoming an issue as the surface snow facets. Have a Merry Christmas!

Summary

Weather Forecast

The arctic air continues to be entrenched over us for the foreseeable future. Lows will be in the low -20's with highs in the -16 to -14 range. Expect light to moderate winds from the NW and sunny skies. A few flurries are forecast for Wednesday but no significant accumulations are expected.

Snowpack Summary

15-30 cm of recent storm snow is facetting quickly with the cold temperatures and starting to sluff more easily in steep terrain. Some wind effect in alpine lee areas. The Dec.15 layer of surface hoar (at tree-line and below), sun crust or facets (depending on location) is down 15-30 cm and some moderate shears have been observed on this interface.

Avalanche Summary

A few small thin wind slabs and loose dry sluffs out of steep terrain have been reported over the last couple days. These have been a result of increased alpine winds, as well as ski cutting or explosive work in steep terrain.

Confidence

Due to the number of field observations

Problems

Wind Slabs

Wind slabs are present in alpine lee areas. So far these have been small and slow to move when triggered, but they could be a concern in steep confined terrain.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Watch for areas of hard wind slab in steep alpine features.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Dry

The cold temperatures are facetting the surface snow and allowing loose dry avalanches to run further than expected in steep terrain. So far they are still very small, but stay aware of this in confined gullies or when skiing steep terrain.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.Be aware of party members below you that may be exposed to your sluffs.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 1

Valid until: Dec 25th, 2017 4:00PM