Avalanche Forecast

Issued: Dec 8th, 2013 8:48AM

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 strong arctic high will gradually start to break down. Weak frontal waves will cross the interior regions, bringing some cloud cover and light snowfall amounts. The next significant change in the pattern should develop mid-week.Monday: Mix of sun and cloud. Alpine temperatures show a high of -18. Ridgetop winds will blow moderate from the SW. Snow amounts near 5 cm.Tuesday: Cloudy. Alpine temperatures show a high of -14. Ridgetop winds will blow light from the West. Snow amounts near 5 cm.Wednesday: Mainly cloudy. Alpine temperatures show a high of -9. Ridgetop winds will blow light from the West. Snow amounts 5-10 cm.

Avalanche Summary

No reports of avalanche activity.

Snowpack Summary

Widespread surface hoar and surface facetting 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 N-NE have developed wind slabs in the alpine and in open areas at treeline on SW-S aspects. These wind slabs may be easier to trigger in areas where a weak layer exists.

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

Unlikely - Possible

Expected Size

1 - 4

Valid until: Dec 9th, 2013 2:00PM