Avalanche Forecast

Issued: Jan 24th, 2014 7:59AM

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

jfloyer, Avalanche Canada

Purcells.

As danger approaches low across the board, it's a good time to remind ourselves that low danger doesn't mean no danger. Food for thought on this blog post.

Summary

Confidence

Good

Weather Forecast

A high pressure ridge will continue to bring dry, warm conditions.Saturday: An inversion will generate an above freezing layer from around 1800 to 3200m. Expect cloud to around 1800 m as well as some strong alpine sunshine. Alpine temperatures will reach around +3C and will feel higher still in the sunshine. Ridgetop winds 20-30 km/h from the NW.Sunday and Monday: Dry, with a mix of sun and cloud, becoming clear by Monday afternoon. Air temperature cooling significantly (expected max of -2C on Sunday and -6C on Monday). Winds light northerly.

Avalanche Summary

Minor sluffing and ski cutting up to size 1 was observed in the new snow on Thursday.

Snowpack Summary

The recent dry, warm weather has generally consolidated the upper snowpack. Old, stubborn hard wind slabs may exist under a skiff of new snow. Steep, sun exposed features are most likely seeing a daily melt-freeze cycle.The biggest concern throughout the region is a layer of weak sugary depth hoar at the base of the snowpack which may coexist with a crust which formed in October. I would continue to be suspicious of any large or unsupported upper elevation slopes, especially if they haven't already avalanched. Possible triggers include a heavy load over a thin spot, a cornice fall or rapid temperature change. Any avalanche failing at this interface would be highly destructive.

Problems

Deep Persistent Slabs

The chance of triggering a deep persistent slab is greatly reduced. However if you were to trigger such an avalanche, the consequences would be great. The most suspect slopes are thin or variable alpine start zones with steep convex sections.

Conditions have improved, but be mindful that deep instabilities are still present.>Caution around convexities or areas with a thin or variable snowpack.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Jan 25th, 2014 2:00PM