Archived

Avalanche Forecast

Dec 8th, 2014–Dec 9th, 2014

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

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

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

Regions: Glacier.

Today is a transitional period for the weather as the approaching front will bring increasing temperatures with moderate to heavy amounts of precipitation. This will cause avalanche hazard to increase.

Weather Forecast

Significant temperature increase over the next 36 hours, freezing level up to 1800m later today and up to 2000m or higher on Tuesday. Moderate to heavy amounts of precipitation expected, possibly falling as rain.

Snowpack Summary

15-20cm of recent storm snow is over the Dec 5 surface hoar/facet layer and sun crust on steep solar aspects. This new snow sits over a breakable crust below 1600m. The Nov 21 and Nov 9 persistent weak layers are buried down ~100 and ~130cm. Snowpack tests indicate triggering the Nov 21 layer as less likely but fracture character is sudden planar.

Avalanche Summary

Small avalanches running to the beginning of runouts.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Avalanche Problems

Storm Slabs

Recent storm snow may be sitting on good sliding surfaces such as surface hoar and crust. Watch for small pockets of slab reactive on steep solar aspects. Expect increasing hazard as the temperature rises.

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. Plan to be off big slopes before the temperatures rises and the snowpack deteriorates.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Persistent Slabs

Trigger points for the persistent weak layers buried down ~1m and ~1.3m include steep alpine terrain, thin areas, and unsupported open slopes.

Be aware of thin areas that may propogate to deeper instabilites.Sluffs may trigger deeper instabilities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3