Avalanche Forecast

Issued: Jan 10th, 2013 8:08AM

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

Alberta Parks mike.koppang, Alberta Parks

There was a decline in Natural avalanche activity on Thursday but conditions are still touchy.  Now is NOT the time for big objective, it IS the time for conservative choices.  Be aware, many accidents happen immediately after a natural avi cycle!

Summary

Confidence

Good

Weather Forecast

The main pulse of the storm is now past us and an arctic high to the north will begin to bring clear skies and cooler temps into the forecast region.  Winds will becoming more NW'erly over the next 24hrs but they are forecast to stay in the moderate to light range.  Lots of snow is available for transport so be sure to keep an eye on the winds and there is a definite potential for some reverse loading over the next few days.

Avalanche Summary

Numerous slab avalanches up to size 2 were observed in steep open terrain below 2150m.  These slides were only 30-40cm deep and likely failing on the 0106SH interface.  In the alpine, numerous slabs avalanche on steep south facing slopes were observed up to size 2.5.  These avalanches were failing within the storm snow and running to the top of their normal runouts.  Numerous loose dry sluffs up to sz 1.5 were also observed.

Snowpack Summary

An additional 24cm of snow fell overnight bringing our totals over the past week to 50cm of snow at lower elevations and closer to 70cm at higher elevations. Widespread storm slabs can now be found in alpine terrain.  These slabs vary from 30-50cm thick.  These slabs are overlying the 0106 Surface hoar/Facet interface.  The surface hoar is most prevalent below 2100m and more spotty in nature above this elevation.  At higher elevations, winds have developed stiff windslabs that are failing on this interface in the easy range in test results.  There was no evidence of any avalanches stepping down to any deeper instabilities.

Problems

Storm Slabs

An icon showing Storm Slabs
Slabs up to 50cm thick are being encountered in all open terrain at treeline and above. Many slides failed on a surface hoar or facet interface down on average 50cm.  Watch for reverse loading with Fridays NW winds.
Be very cautious with gully features.>Avoid cross loaded slopes at or above treeline.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Whumpfing, shooting cracks and recent avalanches are all strong indicators of an unstable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

3 - 5

Loose Dry

An icon showing Loose Dry
Steep terrain continues to produced loose dry avalanches up to size 1.5. These dry avalanches may produce larger storm slab avalanches on underlying slopes so be sure to minimize your exposure to overhead hazard.
Be cautious of sluffing in steep terrain.>Sluffs may trigger deeper instabilities.>Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Valid until: Jan 11th, 2013 2:00PM