Avalanche Forecast

Issued: Jan 26th, 2018 4:00PM

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

Parks Canada stephen holeczi, Parks Canada

We have reached the tipping point for avalanches. Natural activity has slowed down, but the snowpack is perfectly primed for human triggering.  Step way back in terms of your terrain use and exposure.

Summary

Weather Forecast

Temps. will be in the -5 to-10C range for Saturday, and slightly cooler in the alpine. At treeline we could see 10-15cm with light to mod. S - SW upper level winds (3000m). An "atmospheric river" may enter our region Sunday night which could cause an avalanche cycle.

Snowpack Summary

55-75cm of snow has fallen over the past 10 days creating a lot of loose snow on the surface. Alpine winds have distributed this into leeward areas with wind slabs up to 1m thick. Three persistent weak layers lurk in the upper half of the snowpack: Jan 16 down 20-40cm; Jan 6 down 30-50cm; Dec15 down 40-80cm giving easy-mod test results.

Avalanche Summary

There was a widespread avalanche cycle yesterday to size 3 in Little Yoho with wind slabs and persistent slabs failing. Less activity Friday but still some sporadic size 2-3 persistent slabs failing in the region.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs
Lots of recent new snow and winds have created touchy wind slabs in lees.  Yesterday, an avalanche cycle saw many avalanches failing as windslabs and then stepping down to the deeper persistent weak layers
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Avoid all avalanche terrain.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs
There are 3 weak layers in the upper snowpack: Jan 16, Jan 6, and Dec. 15. All are a mix of sun crust, surface hoar and facets depending on your aspect and elevation. Recent loading has overloaded these layers and we are seeing avalanche running far.
It is a good time to stay within the boundaries of a ski resort.Avoid all avalanche terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 27th, 2018 4:00PM