Avalanche Forecast

Issued: Mar 14th, 2017 3:39PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Storm Slabs, Persistent Slabs and Wet Slabs.

triley, Avalanche Canada

Northwest Coastal.

Stormy wet and windy conditions continue. Storm slabs continue to grow in the alpine and natural avalanches are expected.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Wednesday

Weather Forecast

Overnight: The storm continues and freezing levels drop down to 500 metres by morning. This will result in 10-15 cm of new snow combined with strong southwest winds. Wednesday: Another 15-20 cm of new snow above 700 metres with moderate southwest winds. Thursday: A bit cooler with daytime freezing levels around 500 metres, moderate southerly winds and 5-10 cm of new snow. Friday: Strong southwest winds and 10-15 cm of new snow.

Avalanche Summary

Several wet slab avalanches size 2.5 were reported on Tuesday from the Bear Pass area. I suspect that a natural avalanches cycle is ongoing today. Reports may be limited by poor visibility and travel conditions.

Snowpack Summary

Storm slabs continue to develop above 1100 metres. These storm slabs are deep 30-60 cm, with much deeper areas where the wind has transported the snow. Below 1100 metres the snow is moist or wet. The overall results will be widespread touchy storm slabs at higher elevations and unstable wet snow at lower elevations. The storm snow is also stressing a weak interface from February composed of facets, crust, and surface hoar buried over a metre deep. Given the recent activity on this layer before the storm, it should be very reactive during this storm. The lower snowpack is strong, with the exception of basal facets in shallow snowpack areas around Bear Pass and Ningunsaw.

Problems

Storm Slabs

Storm slab avalanches are expected to continue due to forecast snow and wind.

Travel in avalanche terrain is not recommended with current conditions.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

2 - 3

Persistent Slabs

The natural storm slab cycle is expected to release persistent slab avalanches. Cornice falls may trigger deeply buried persistent weak layers.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Avoid all avalanche terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 4

Wet Slabs

Heavy rain on snow may trigger wet slab or loose wet avalanches at lower elevations. This problem may be short lived due to the forecast cooling trend.

Use extra caution on slopes if the snow is moist or wet.If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 15th, 2017 2:00PM