Avalanche Forecast

Issued: Dec 15th, 2014 4:00PM

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

tim haggarty, Parks Canada

Waterton Lakes.

The snowpack is gaining strength as it begins to refreeze following a major warm up. Caution and active investigation of the snowpack is still warranted in the Alpine. Below treeline the heating has reduced coverage from poor to really poor.

Summary

Weather Forecast

It looks like good weather for the period: mild temperatures: -10 to -3 at Little Prairie with thin cloud cover. The West wind will likely cause the biggest change to the snowpack and is very likely to redistribute the 10 to 20 cm available above the Dec 13 crust

Snowpack Summary

With heating and rain last week, the entire snowpack to at least 2200m went to zero degrees or became "isothermal" . As temperatures dropped over the weekend a surface crust formed that was thankfully buried by 10 to 20 cm of new snow. Beneath the crust the snowpack is now beginning to refreeze giving it considerable strength Treeline and below.

Avalanche Summary

Only minor loose dry activity with the new snow running over the surface crust has been seen.

Confidence

Due to the number and quality of field observations

Problems

Persistent Slabs

Following significant heating, these slabs are gaining strength as they refreeze. The facets and associated crust found near the base of the snowpack likely only remain a problem at elevations above at least 2400m but we have not traveled this high.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 3

Loose Dry

The new snow moves naturally and with skier traffic above the surface crust. Use caution in confined terrain such as gullies or in high consequence terrain such as above cliffs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

After a completely calm two days since the new snow fell, the wind is just now beginning to stir. Expect to find freshly formed windslabs in the days to come.

Avoid freshly wind loaded features.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 18th, 2014 4:00PM