Avalanche Forecast

Archived

Jan 27th, 2014–Jan 28th, 2014

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Northwest Inland.

Freezing levels are dropping and some new snow is on the way. Deep persistent slab problems may still exist in isolated areas. Please see blog post for more information.

Confidence

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

Weather Forecast

Overnight and Tuesday: The inversion is forecast to break down overnight, resulting in freezing levels dropping down to about 1500 metres by morning. Light precipitation is expected to start as freezing levels lower, expect 5-7 cm by morning with light to moderate Southwest winds. Expect another 3-5 cm during the day.Wednesday: Continued light precipitation and freezing levels dropping down to valley bottoms as winds shift to Northwest and build to moderate values.Thursday: Chance of a few more cm of snow before the winds shift to the Northeast and become strong as colder air moves into the region.

Avalanche Summary

No new avalanches reported. Forecast cooling temperatures should put an end to loose wet avalanche problems.

Snowpack Summary

A report from the Bulkley Valley shows widespread surface hoar development over the past few clear days and nights. I suspect that the solar radiation at upper elevations destroyed some of those well formed crystals. Dropping freezing levels as the temperature inversion breaks down should create a solid re-frozen surface crust. Forecast new snow may not bond well to the crust or the new surface hoar.

Problems

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.