Avalanche Forecast

Issued: Feb 17th, 2014 4:00PM

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

tim haggarty, Parks Canada

Waterton Lakes.

A good time to avoid avalanche terrain. With more snow and wind in the forecast the touchy conditions will continue to deteriorate as the potential size of natural avalanches increase.

Summary

Weather Forecast

Snowfall is forecast to continue overnight Monday. Gusty SW/W winds will also continue with freezing levels near valley bottom. There should be a lull before the next system hits late Tuesday with 10-15cm and another 10 cm inbound for Thursday morning. Generally, rapid loading will continue and natural activity should be expected.

Snowpack Summary

Up to 80 cm now buries a significant weak layer found on all aspects and elevations. Gusty West winds and mild temperatures have contributed to widespread slab formation especially in open areas. More loading and wind will increase the serious nature of these surface storm slabs. Weak snow at the base of the snowpack also remains a concern.

Avalanche Summary

A skier was caught and buried in an avalanche Saturday that the party triggered while descending Rowe Peak at around 2300m on NE-E aspect. Widespread natural activity is occurring with the continued rapid loading due to strong winds and snow. Long propagations and the potential for remote triggering have created dangerous conditions for travelers

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

These recently formed slabs have proven to be very easy to trigger failing naturally and with light loads. Limit your exposure to significant slopes. Do not get taken by surprise by the long propagations that are occurring.

Choose conservative lines and watch for clues of instability.Avoid open slopes with any steepness over 30 degrees.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Deep Persistent Slabs

Do not forget that there is weak snow under the entire snowpack. In shallow areas this faceted snow has continued to weaken and the slab above it that is holding the snowpack together has become stressed by recent loading.

Be aware of thin areas that may propogate to deeper instabilites.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Feb 20th, 2014 4:00PM