Avalanche Forecast

Issued: Dec 9th, 2012 9:23AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs and Deep Persistent Slabs.

mbender, Avalanche Canada

Northwest Inland.

Summary

Confidence

Poor - Timing, track, or intensity of incoming weather is uncertain for the entire period

Weather Forecast

Monday: : Light to Moderate precipitation with westerly and southwesterly winds 30-50km/h gusting to 90km/h. Freezing levels expected at 700m with alpine temperatures -6 degrees.Tuesday: Light precipitation, temperatures cooling to -9 in the alpine. Winds southwesterly moderate to strong.Wednesday: Light flurries, winds light from the northwest and alpine temperatures -8.Â

Avalanche Summary

There is no new avalanche activity to report at this time.

Snowpack Summary

Windslab instabilities exist in the upper snowpack at treeline and in the alpine from recent snowfall accompanied by moderate to strong winds. Treeline snow depths range between 90-125 cm. Snow depths in the alpine are highly variable with deep wind drifts and heavily scoured slopes in exposed areas. A layer of small surface hoar crystals exists at tree-line in isolated sheltered areas. This is most likely buried down 20-35 cm. A weak layer of facets sitting on a crust exists near the base of the snowpack down 90-140 cm. We do not have much information on the reactivity of this layer. If you are traveling in the backcountry, send us your observations. Every bit of information helps us to create a better product. Email us at forecaster@avalanche.ca

Problems

Wind Slabs

New snow and strong west and northwesterly winds have created windslabs in the lee of terrain features. Strong winds often create slabs that extend further down the slope than expected and in open areas below treeline.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

Deeply buried facet/crust weaknesses are often prone to remote triggering and step down avalanches. Typical trigger points include thin rocky areas. They may be difficult to trigger, but deep persistent slab avalanches are often very large.

Carefully evaluate and use caution around thin snowpack areas.>Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Dec 10th, 2012 2:00PM