Archived

Avalanche Forecast

Dec 9th, 2014–Dec 10th, 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

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 Coast.

Avalanche danger will stay elevated as long as the stormy weather continues.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Continued light to moderate rain, or wet snow, is expected for Wednesday with another 10-20 mm of precipitation with associated moderate but gusty southerly alpine winds, as freezing levels hover around 2000 m. Thursday could see another 5-15 mm of rain (or cm of wet snow) with associated moderate but gusty southwesterly winds as freezing levels drop as low as 1500 m. While Friday looks dry with a mix of sun and cloud, light alpine winds, and freezing levels back to valley bottoms.

Avalanche Summary

No new reports of avalanches. Please let us know what you're seeing out there. Submit your observations to the Mountain Information Network.

Snowpack Summary

Heavy rain is saturating the upper snowpack and resulting in wet, loose, and cohesionless surface snow as high as alpine elevations in the southern part of the region. While in the alpine and as low as treeline elevations further north wet snow and wind has formed new storm slabs and is overloading previous weaknesses buried within the snowpack, such as the mid-November crust-facet layer. Snow pack depth and snow quality drastically diminishes as you drop below treeline.

Avalanche Problems

Storm Slabs

Heavy snow at alpine elevations is expected to form dense storm slabs and overload existing weaknesses. Very strong southerly winds may also create deep wind slabs in Northwest-Northeast facing terrain well below ridge crests.

Choose well supported terrain without convexities.>Use ridges or ribs to avoid wind loaded and cross loaded slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3

Loose Wet

Expect heavy loose wet sluffs in steep open terrain and in gullies. Although not expected to be large avalanches, they could knock you off your feet and have serious consequences if terrain traps are below.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Be aware of party members below you that may be exposed to your sluffs.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3