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Archived

Avalanche Forecast

Feb 16th, 2014–Feb 17th, 2014
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
2: Moderate
The avalanche danger rating below treeline will be moderate
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
2: Moderate
The avalanche danger rating below treeline will be moderate
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: Northwest Inland.

Confidence

Fair - Due to the number of field observations

Weather Forecast

A series of frontal systems will be sending waves of light precipitation amounts accompanied by strong southwesterly winds. Model runs are in agreement with timing and precipitation amounts.Sunday night: Snow amounts 5 cm. Ridgetop winds blowing strong from the SW gusting strong. Monday: Snow amounts 5-10 cm. Alpine temperatures -5.0. Moderate SW ridgetop winds with strong gusts. Tuesday: Snow amounts 5-10 cm. Alpine temperatures near -6.0. Ridgetop winds moderate from the SW.Wednesday: Trace. Alpine temperatures near -7.0 with light SW ridgetop winds.

Avalanche Summary

No new avalanche activity has been reported. Reports from the Coastal region have seen natural slab avalanches up to size 2, additionally some larger size 2.5 were triggered with explosives control. Numerous size 1-2 skier remote (up to 50 m away) slab avalanches released down 60 cm all on the old buried surfaces mentioned above in the snowpack summary. A poor bond exits with the new snow and old surfaces; however I think the Inland region lacks  the snow amounts to be as reactive as the Coastal region. I would be suspicious of wind loaded slopes at all elevations, use conservative terrain choices and make observations as you travel.

Snowpack Summary

The region has received between 30-55 cm of new snow which overlies a variety of old surfaces. These buried surfaces consist of weak surface facets, surface hoar (more predominant at treeline and below treeline elevations), a scoured crust, wind press, or any combination of these. Whumpfing, cracking and reports from the field indicate a very poor bond between the new snow and these old surfaces. Strong winds and slight warming may have added cohesion to the new storm slab, and have shifted the new snow into deeper, and potentially destructive wind slabs in exposed terrain.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

Wind Slabs

30-55 cm of recent snow and strong SW winds have built touchy wind slabs on lee slopes. Storm slabs at treeline and below may be reactive to rider triggers. Whumpfing, cracking and avalanches are direct indicators of a buried weak layer.
Choose conservative lines and watch for clues of instability.>Avoid freshly wind loaded features.>

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

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 4