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Avalanche Forecast

Feb 12th, 2014–Feb 13th, 2014
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable

Regions: Sea To Sky.

Confidence

Fair - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

Thursday: Moderate to locally heavy snowfall / Strong southwest winds / Freezing level at 1000mFriday: Heavy snowfall / Strong southwest winds / Freezing level at 1200mSaturday: Moderate snowfall / Moderate southwest winds / Freezing level at 1100m

Avalanche Summary

Numerous natural and human-triggered storm slabs to size 2.5 were observed on Tuesday and Wednesday. In at least one case, an avalanche was triggered remotely from a distance of 30m. This speaks to the touchy nature of the current instability.

Snowpack Summary

Between 50 and 80cm of recent snowfall overlies a medley of old surfaces which include: weak surface facets, surface hoar, thin wind slabs, a scoured crust, or any combination thereof. Professionals are expressing particular concern for the combination of buried facets on a crust being unusually reactive at lower elevations. Reports of whumphing and widespread avalanche activity further indicate a poor bond between the new snow and these old surfaces. Strong to extreme winds are shifting the new snow into deeper, reactive wind slabs in exposed terrain. With forecast warming and more snow on the way, the reactivity and destructive potential of the new storm slab will likely increase.The mid and lower snowpack are generally strong and well-settled. Basal facets and depth hoar are likely to exist in some parts of the region, but triggering has become unlikely.

Avalanche Problems

Storm Slabs

A touchy and destructive storm slab, which has shown reactivity at all elevation bands, sits over a variety of potentially weak surfaces. Conservative terrain selection has become critical.
Use conservative route selection, stick to moderate angled terrain with low consequence.>The touchy conditions will require extreme caution if traveling in the mountains.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 1 - 5