Avalanche Forecast

Issued: Mar 15th, 2016 3:00PM

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

Alberta Parks matt.mueller, Alberta Parks

Continuous flurries are keeping the hazard consistent these days. That trend will continue for awhile yet. Many large slopes have not yet avalanched this season and appear very fat. Treat big terrain with caution-especially if it hasn't avalanched.

Summary

Confidence

High

Weather Forecast

Cloudy with sunny periods and isolated flurries tomorrow. The alpine high will be -8 with a 1300m freezing level. Winds will out of the NW and average 40km/hr.

Avalanche Summary

One notable avalanche was seen today. It was a healthy sz2.5 on a north east aspect, alpine feature in the northern part of the forecast region. It was immediately below a large headwall and was at 2400m. The deposit wasn't visible, so the size is an estimate. If it stepped it may be a sz3.

Snowpack Summary

Ongoing convective flurries continue to add the the snowpack daily. At treeline, we now have 20-30cm of recent snow on top of the March 8th layer. This interface is slow to improve, but so far the slab density above it is soft and only a concern in the upper reaches of the  treeline zone. The Feb 11th layer is down 40cm and the Feb 27th is down 50-60cm. In all cases the bond is healing, but still something to watch. 2150m seems to be the magic number when it comes to the crusts disappearing. South aspects may vary depending on angle. Interestingly, the Jan 6th layer appears to be getting worse as the surface snow settles and gains some density. At treeline we are finding that layer to be down about 1m and reacting in tests. The alpine is currently going through another windloading event. Slabs from transport and settlement were noted today in any open terrain. The soft slabs are dense enough to propagate in the right terrain (steep & convex).

Problems

Wind Slabs

An icon showing Wind Slabs
There are fresh, alpine windslabs forming at the moment. The snow temps are perfect for wind slabs and wind "pressing". Beneath these new slabs are a variety of older slabs that extend down to treeline. Probing will help indicate where they are.
Avoid steep slopes below cornices.>Choose well supported terrain without convexities.>Avoid freshly wind loaded features.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
This layer is starting to get our attention again. As the new treeline snow settles, the burial depth is staying relatively constant at 1m. Keep an eye on where thin spots may be present and avoid shallow areas at all elevations.
Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Cornices

An icon showing Cornices
These are growing by the day! Remember that they can fall off at any time regardless of current weather conditions. Avoid spending any time under, or over them.
Pay attention to overhead hazards like cornices.>Stay well back from cornices.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Mar 16th, 2016 2:00PM

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