Avalanche Forecast

Issued: Feb 18th, 2018 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

Some areas have extensive windslabs down into treeline while in some areas there is less affect.  Forecasters are still avoid large overhead features that havent released.

Summary

Confidence

Moderate -

Weather Forecast

Cold temps, light northerly winds and no new precip is the theme for the next few days!  Be on slopes with a solar aspect to make the day more enjoyable!  -26's are a theme for the next few days.

Avalanche Summary

No new avalanche activity was observed.

Snowpack Summary

5-10cm of recent snow is overlying windslabs in some areas that are up to 30cm thick.  These windslabs seem to be very variable in terms of extent and location.  On Saturday only minimal slabs were encountered at treeline and then on Sunday in the Heros Bowl area, windslabs well down into treeline caused forecasters to turn around.  Where these slabs are being observed they are failing in the easy to moderate range down 20-40cm.  Deeper in the snowpack the December and January layers can still be found.  Hard results in snowpack tests that are sudden planar in nature indicate that this layer may be getting harder to trigger, but if it goes it will be a large avalanche.  In general these layers are down 100-140cm so be curious and dig and examine.

Problems

Wind Slabs

An icon showing Wind Slabs
Widepsread windslabs in Alpine terrain and more variable at treeline locations.  Some areas there has been winds well down into the timber and others not so much.
If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs
Hard and sudden planar results are being observed on this layer down in general 120cm.  Its getting harder to trigger but will result in large avalanches.
Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1.5 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Recent avalanche activity has shown the potential for avalanches to step down to this layer.
Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Feb 19th, 2018 2:00PM

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