Avalanche Forecast

Issued: Mar 23rd, 2013 4:00PM

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

Snow Safety, Parks Canada

Banff Yoho Kootenay.

Many bold tracks have shown that not all slopes are avalanche prone. The conditions are tricky. Do not let the presence of other tracks dissuade you from a conservative fun day. JBW

Summary

Weather Forecast

Another sunny day under a ridge of high pressure will be followed by a weak front and a few clouds Monday.

Snowpack Summary

There is a great variation between the east and west in the forecast district. East of the divide, the lower snowpack is weak facets and collapsing of this layer is causing remote triggering of avalanches with wide propagations. On southerly aspects these avalanches are failing on a crust while on NE aspects cornice triggers are triggering storm.

Avalanche Summary

Natural avalanches have been observed on all aspects every day for the past week, some up to size three. These avalanches are more prevalent east of the divide.

Confidence

Due to the quality of field observations

Problems

Persistent Slabs

Watch out for thin areas especially East of the divide where it is possible to trigger or remote trigger deep slabs on basal facets or crusts.� Be conservative with terrain choices in bigger terrain.

Avoid shallow snowpack areas where triggering is more likely.Choose the deepest and strongest snowpack areas on your run.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

New windslabs have formed on lee aspects, much thicker West of the divide where more new snow has fallen.

Avoid lee and cross-loaded terrain near ridge crests.The recent snow may now be hiding windslabs that were easily visible before the snow fell.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Cornices

There have been a number of cornice falls observed over the last week, some triggering deep storm slabs beneath. Be aware of what is above you.

Extra caution needed around cornices with current conditions.Cornices become weak with daytime heating, so travel early on exposed slopes.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 24th, 2013 4:00PM