Archived

Avalanche Forecast

Jan 10th, 2015–Jan 11th, 2015

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

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

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 Rockies.

Keep the persistent slab problem in mind when you choose terrain this week. The likelihood of triggering it may be low, but the consequences could be high.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Only trace amounts of snow are expected throughout the forecast period. Overcast conditions are forecast for Sunday, although skies should become increasingly clear on Monday and Tuesday as a dry ridge of high pressure becomes the dominant air mass. Ridgetop winds should remain generally light, while freezing levels will remain at valley bottom.

Avalanche Summary

No recent avalanches have been reported.

Snowpack Summary

Below treeline and on south-facing slopes there may be a melt-freeze crust overlying up to 20 cm of recent snow. At higher elevations the new snow has been blown into wind slabs in exposed lee terrain. The recent snow sits on hard wind slabs in exposed terrain, and low density faceted snow in sheltered areas. Up to 75 cm below the surface you will likely find a hard, thick crust which formed mid-December. This crust has overlying facets and surface hoar (up to 10 mm in sheltered locations at treeline and below). This layer seems variably reactive throughout the region. In areas where the overlying slab is thick and cohesive, large avalanches are possible at this interface. A crust/facet combo which formed in November seems to have gone dormant for the time being.

Avalanche Problems

Wind Slabs

Recent West or Northwest winds have probably created fresh wind slabs in exposed lee terrain.

Be cautious as you transition into wind affected terrain.>Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Persistent Slabs

A buried persistent weakness, down 30-50 cm, should remain on your radar as it has the potential to produce large avalanches.

Avoid convexities or areas with a thin or variable snowpack where triggering could be more likely.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 4