Avalanche Forecast

Issued: Dec 26th, 2017 4:00PM

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.

brian webster, Parks Canada

Banff Yoho Kootenay.

Sluffing is becoming an issue as the surface snow facets. Dress warm and enjoy the holidays!

Summary

Weather Forecast

The arctic air continues to be entrenched over us for the foreseeable future. At treeline overnight lows will be in the low -20's with day time highs in the -16 to -14 range. Expect light to moderate winds from the NW with a mix of sun and cloud. A few isolated flurries are forecast for Wednesday but no significant accumulations are expected.

Snowpack Summary

Upper snow-pack is facetting with the cold temperatures and starting to sluff easily in steep terrain. Some thin, hard wind slabs observed in lee areas in the alpine. The Dec.15 layer of surface hoar (below 2100m) and hard surfaces or facets (depending on location) is down 15-30 cm. Some moderate shears have been observed around this interface.

Avalanche Summary

Only a few small thin wind slabs and loose dry sluffs out of steep terrain have been reported over the last four days.

Confidence

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.

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.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 1

Valid until: Dec 27th, 2017 4:00PM