Avalanche Forecast

Issued: Jan 16th, 2017 3:33PM

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

shorton, Avalanche Canada

Northwest Inland.

Large destructive avalanches remain likely due to ongoing snow, rain, wind, and warming. Stick to mellow terrain and avoid overhead hazards.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Tuesday

Weather Forecast

MONDAY NIGHT: Scattered flurries with up to 5 cm of new snow, strong southwest winds, freezing level around 700 m. TUESDAY: Another storm pulse brings 5-15 of new snow, strong southwest winds, freezing level around 1100 m.WEDNESDAY: Flurries with up to 5 cm of new snow, moderate southwest winds, freezing level around 1000 m.THURSDAY: Clearing with isolated flurries, moderate southwest winds, freezing level around 800 m.

Avalanche Summary

Poor visibility has limited avalanche observations during the storm. Recent reports include a size 1 skier triggered storm slab near Kispiox and an audible natural avalanche in the southwest part of the region.Triggering storms slab avalanches will remain likely in areas that receive heavier snowfall over the next few days. However, the primary concern throughout the region is the deep persistent slab problem, as large destructive avalanches remain likely with ongoing warming and loading.

Snowpack Summary

Expect another 10-20 cm of new snow by Tuesday, bringing recent storm snow totals to 20-40 cm in the southern part of the region. With strong winds and rising freezing levels, expect touchy storm slabs throughout the week. The new snow has buried a layer of feathery surface hoar crystals, which will allow for wide propagations in the storm snow.Snow depths at treeline vary from about 1 m in most areas to 2 m in deeper snowpack areas in the south and west of the region. The shallow snowpack areas mostly consist of weak faceted or sugary grains beneath hard slabs. With the additional load of new snow and rain, these hard slabs may produce surprisingly long fractures resulting in large avalanches, and in some instances they may step down to weak faceted snow near the ground.

Problems

Deep Persistent Slabs

The potent mix of snow, rain, wind, and warm temperatures will keep the likelihood of natural and human triggered deep destructive avalanches elevated throughout the week.

Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.Stick to simple terrain and be aware of what is above you at all times.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Storm Slabs

New snow, warm temperatures, and strong winds have created a widespread storm slab problem, particularly on wind-loaded features. Storm slab avalanches in motion may step down and trigger deep persistent slab avalanches.

The new snow will require several days to settle and stabilize.Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Jan 17th, 2017 2:00PM