Avalanche Forecast

Issued: Dec 27th, 2013 8:31AM

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

jon stuart-smith, Parks Canada

Waterton Lakes.

The early season conditions still present a considerable risk, be careful of rocks and stumps that are lurking under the snow surface. The danger could increase with new snow on Friday night, especially if we receive more than the 5 cm forecast.

Summary

Weather Forecast

A cold front forecast to pass over the area in Friday night will drop temperatures and bring some precipitation. Ahead of the front there could be some rain but as the temperatures drop there could be up to 10 cm of new snow. . Winds should die down and switch to the northeast with the passing of the front.

Snowpack Summary

Extreme SW winds over the last 24 hrs and warm temps have created hard slabs with the remainder of the snow from earlier this week. Gullies and wind loaded features have a series of windslabs with all wind exposed slopes scoured. The Faceted Crystals associated with the Nov Crusts are buried 50 to 70 cm, a weak layer that remains of interest.

Avalanche Summary

No new avalanche activity has been observed.

Confidence

Due to the number of field observations

Problems

Wind Slabs

Recent strong SW winds have built windslabs at ridgelines and gully features. Warm temperatures have likely helped strengthen these slabs but triggering is still a possibility.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Weak snow associated with crusts formed in Mid and early November can be found down about 70cm. This seems to be less significant on Southerly aspects. Triggering planar slopes from thin areas remains a possibility to consider.

Dig down to find and test weak layers before committing to a line.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 30th, 2013 4:00PM