Avalanche Forecast

Issued: Feb 29th, 2016 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

We are back to a "Classic Rockies" mid winter snowpack with a weak structure that does not inspire confidence and will linger for some time. Low likelihood, high consequence periods like this are best managed with conservative decision making.

Summary

Weather Forecast

Flurries Tues night and into Weds will produce small amounts of snow on the ground (~5cm). Wind will remain light to moderate from the west. Freezing levels will remain below surface.

Snowpack Summary

Treeline height of snowpack values range from 100 to 170cm. The Feb 11 layer of sun crust and isolated surface hoar is down 20 to 50cm. The Jan 6 layer of faceted crystals is the dominant snowpack feature and is down about 50-70cm. This layer is producing whumpfing, cracking and has been responsible for much of the recent avalanche activity.

Avalanche Summary

No new avalanches to report.

Confidence

Due to the number of field observations on Tuesday

Problems

Deep Persistent Slabs

Generally the snowpack has a weak midsection throughout the BYK region. Both the Feb 11 and Jan 6 layers produce significant shears in tests. Human triggering of large avalanches that could step down to the ground is a real possibility.

Watch for signs of instability such as whumpfing, or cracking. Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

The possibility of small windslabs exists in alpine lee areas. Watch for these at the local level.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 1st, 2016 4:00PM