Avalanche Forecast

Issued: Dec 10th, 2013 8:34AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Persistent Slabs.

swerner, Avalanche Canada

South Rockies.

Summary

Confidence

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

Weather Forecast

The region will see light snowfall amounts, gradual warming and strong ridgetop winds as the warm front of the pacific frontal system arrives on Wednesday. A series of disturbances will continue through the forecast period with the timing and intensity tricky to predict. Wednesday: Cloudy. Snow amounts 5-10 cm. Alpine temperatures near -11. Ridgetop winds moderate from the SW. Thursday: Cloudy with flurries near 3-5 cm. Alpine temperatures near -9. Ridgetop winds moderate, gusting strong from the SW.Friday: Cloudy with some sunny periods. Snow mounts near 5 cm. Alpine temperatures -6. Ridgetop winds light from the SW.

Avalanche Summary

On Monday a size 1.5 rider triggered wind slab avalanche was reported. It was easily triggered and It failed on a NE aspect around 2200 m.

Snowpack Summary

Widespread surface hoar and surface faceting continue to develop. Snowpack depths at treeline seem to vary from 50 - 110 cm. Widespread wind effect is noticeable in the alpine and at treeline.Down 30-40 cm sits a surface hoar/ facet/ crust interface. Snowpack testing showed easy results and some whumphing (failure of a weak layer below your feet). If you're seeing or feeling this, consider it a direct indicator of a buried weakness below.Near the base of the snowpack, weak sugary facets exist. This layer may be stubborn to trigger, especially in deeper snowpack areas. In shallower locations the likelihood may increase especially on a steep, convex slope. In some areas its still below threshold below treeline, and early season hazards like open creeks, and stumps exist.

Problems

Wind Slabs

Winds from the SW have developed wind slabs at higher elevations on lee slopes and behind terrain features. Use extra caution around cross-loaded areas.

Be cautious as you transition into wind affected terrain.>Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Sugary facets at or near the base of the snowpack likely represent the most worrisome persistent layer at this time. The most likely place to trigger them is on steep, convex slopes with a thin snowpack.

Conditions have slightly improved, but be mindful that deep instabilities are still present and may be rider triggered.>Avoid shallow snowpack areas on steep, convex terrain where triggering is more likely.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Dec 11th, 2013 2:00PM