Avalanche Forecast

Issued: Jan 20th, 2015 8:00AM

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

percy woods, Parks Canada

Glacier.

January 15th surface hoar layer is reactive and has a ready storm slab sitting on it waiting for a trigger.

Summary

Weather Forecast

Below freezing temperatures, limited precipitation, light to moderate Southerly winds and the possibility of the sun coming out are the forecast for the next couple of days. Solar triggered slides may occur on steep solar aspects with prolonged sun exposure

Snowpack Summary

45cm of storm snow overlies the January 15 surface hoar layer and on steep due south terrain a sun crust. Strong south through west winds have redistributed the storm snow onto alpine lee slopes and ridges. Wind effect has caused surface slabs and heavy skiing. The December 17 surface hoar layer is down 80-130cm sitting on a crust below 2100m.

Avalanche Summary

A widespread natural avalanche cycle occurred yesterday and into last night. Large avalanches up to size 3 were observed and reported yesterday afternoon both in the back country (Connaught Creek) and the highway corridor. Human triggered slides were reported on McGill two days ago. The January 15 layer is touchy and reactive.

Confidence

Due to the number and quality of field observations

Problems

Storm Slabs

45cm+ of storm snow sits on the weak reactive January 15 surface hoar layer. Numerous natural avalanches to size 3 and skier triggered slides to size 2 have occurred over the last couple days on this layer.

Watch for whumpfing, hollow sounds, and shooting cracks.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

The December 17 layer may reawaken after being overloaded by slides initiating on the January 15 surface hoar layer. This layer is widespread at treeline and spotty at alpine elevations.

Be wary of slopes that did not previously avalanche.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

1 - 3

Valid until: Jan 21st, 2015 8:00AM