Avalanche Forecast

Issued: Feb 9th, 2018 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

This weekend limit your exposure to avalanche terrain.  Recent snow has overloaded the snowpack triggering large avalanches.  Special Public Avalanche warning is in effect.  Click Here

Summary

Confidence

High -

Weather Forecast

No new snow is expected over the next 24hrs but we are expecting the winds to increase out of the NW into the moderate range.  Temperatures will be a bit more seasonal with -12c.  Already solar radiation is starting to play a role in terms of stability. Avoid being under steep solar aspects as conditions warm up.

Avalanche Summary

This was our first good day to look around and we saw widespread avalanche activity up to sz 3.5 on all aspects and at all elevations.  When the sun did come out, solar aspects became more reactive and natural avalanche activity was observed later in the day in these areas.  A popular run know as "Purple Bowl"  what we call the Dog Leg Slide path released size 3 taking out all previous tracks and running full path to its historic run outs.  Many fracture lines at treeline were also observed down 1m likely failing on the Jan 6th SH layers. 

Snowpack Summary

Solar radiation played a big role on friday as the sun is beginning to have enough punch to begin to make the snow moist on steep solar aspects later in the day.  The solar input triggerred rapid settlement and avalanche activity up to sz 3 on solar aspects.  We are still dealing with a complex, reactive snowpack at this time.  Wind slabs in the upper snowpack as well as the deep persistent problems are our major concerns at this time.  The recent snow is overloading the myriad of weak layers that we currently have within the snowpack and causing widespread large destructive avalanches.  Many of the weak layers are 100-150cm deep so evaluating them in field tests is challenging.  This weekend will be a good time to stay out of avalanche terrain and minimize your exposure to overhead hazards. 

Problems

Wind Slabs

An icon showing Wind Slabs
Found at treeline and above up to 50cm thick. They are being found on all aspects due to reverse loading patterns of recent winds.
If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Select routes that do not travel in or under avalanche terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

2 - 3

Persistent Slabs

An icon showing Persistent Slabs
Widepsread avalanche activity observed recently stepping down to the persistent deep layers such as Jan 6th Surface hoar and the Dec 15th Facet surface hoar interface. 
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3.5

Storm Slabs

An icon showing Storm Slabs
Watch for these problems at treeline and below where the recent snow has settled into a reactive slab. 
Select routes that do not travel in or under avalanche terrain.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Valid until: Feb 10th, 2018 2:00PM