Avalanche Forecast

Issued: Dec 9th, 2013 8:06AM

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

Poor - Due to the number of field observations

Weather Forecast

The arctic ridge will persist today. By mid- week a significant change will take place in the current weather pattern as a pacific frontal system brings precipitation, warmer temperatures and strong winds from the West.Tuesday: Mainly cloudy. Alpine temperatures show a high near -15. Ridgetop winds light from the SW. Wednesday: Cloudy with snow amounts near 5 cm. Alpine temperatures show a high of -10. Ridgetop winds moderate from the SW.Thursday: Cloudy. Alpine temperature shows a high of -7. Ridgetop winds moderate from the SW gusting to strong.

Avalanche Summary

No reports of avalanche activity.

Snowpack Summary

Widespread surface hoar and surface faceting continues to develop. Snowpack depths at treeline seem to vary from 80 - 120 cm. Strong ridgetop winds from the N-NE has redistributed snow onto S-SW aspects, creating reverse loaded slopes. Widespread wind effect is noticeable in the alpine and at treeline, but reports suggest wind slabs are stubborn to trigger.Below the recent storm snow 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, I suspect you will find sugary weak facets. This layer may be stubborn to trigger under the current conditions, but if it was to happen, it would most likely be on a steep, convex slope with a thin snowpack

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

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.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Dec 10th, 2013 2:00PM