Avalanche Forecast

Issued: Jan 19th, 2015 8:12AM

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

Parks Canada ali haeri, Parks Canada

Reactive surface hoar layer with many rider triggered avalanches! The storm hit with strong winds and has slabbed up the snow. Combined with mild temperatures, the slab over the surface hoar layer will be more cohesive and propagation will increase.

Summary

Weather Forecast

Unsettled weather will persist into Tuesday with light snow and cloud. Temperatures are on a cooling trend and winds will be tapering down as a ridge of high pressure builds over the southern half of the Province into Wednesday.

Snowpack Summary

Close to 20cm of new snow overnight bringing recent storm snow to 45cm overtop the widespread Jan 15 surface hoar layer and crust on solar aspects. Expecting wind effected snow at higher elevations. The Dec 17 surface hoar layer is down 90-130cm overlying a crust below 2100m. The Nov 9 crust is a basal layer at the bottom of the snowpack.

Avalanche Summary

Backcountry users and field teams reporting several remote and rider triggered avalanches to size 1.5 down 20-50cm running on the Jan 15 surface hoar layer. Cheops North 4,natural avalanche dusted two riders on the uptrack. Natural avalanche cycle up to size 3.0 within the highway corridor began yesterday afternoon and into early this morning.

Confidence

Due to the number of field observations

Problems

Storm Slabs

An icon showing Storm Slabs
~50cm of new snow overtop the widespread Jan 15 surface hoar layer. This layer was very reactive to human triggering yesterday. Expect this sensitivity to continue with the storm slab that formed overnight with the sustained strong southerly winds.
Be cautious as you transition into wind affected terrain.Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
The new snow load or shallower avalanches could reawaken the Dec 17 surface hoar layer down 90-130cm. This layer is widespread at treeline, more spotty at alpine elevations and sits on a thick crust complex.
Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 20th, 2015 8:00AM