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Avalanche Forecast

Dec 20th, 2015–Dec 21st, 2015
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: South Rockies.

Winds are making a mess of things up high. The best and safest riding is probably in the shelter of the trees.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

A series of frontal systems is expected over the next three days, bringing light snow and moderate to strong SW ridge top winds. The freezing level stays near 800 m. Late on Wednesday an arctic ridge starts to build. Snowfall in the south (less in the north): Monday – 5-10cm; Tuesday – 5-10 cm; Wednesday – 2-5 cm. For more details check out https://avalanche.ca/weather.

Avalanche Summary

Skiers triggered size 1 loose dry avalanches on Saturday.

Snowpack Summary

The series of recent storms has left us with around 40-60 cm new snow sitting on a firm rain crust. For the most part, the new snow has bonded well to this rain crust, although potentially unstable wind slabs could exist where wind-pressed snow rests directly on a slippery crust below. A previous weak layer from early December consisting of crust, surface hoar, and/or facets and is typically down 70-90 cm. Around 20-30 cm below this interface is a rain crust from mid-Nov with a thick layer of facets below it. Both the early-Dec and mid-Nov layers have become dormant and are likely being capped at treeline and below by the more recent rain crust layer. However, these layers may still be reactive to heavy triggers such as cornices or smaller avalanches stepping down.

Avalanche Problems

Wind Slabs

Strong SW winds have created fresh sensitive wind slabs that will mainly be a problem in the alpine, but you may find the odd wind loaded feature at treeline too.
Use conservative route selection, stick to moderate angled terrain with low consequence.>Watch for areas of hard wind slab in steep alpine features.>Avoid freshly wind loaded features and use ridges/ribs to sneak around these problem areas.>

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 4