Avalanche Forecast

Issued: Feb 23rd, 2015 3:00PM

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

matt.mueller, Alberta Parks

Kananaskis.

High northern aspects are the place to look for good snow at this point.

Summary

Confidence

Good

Weather Forecast

A cloudy day tomorrow should keep the solar aspects a bit cooler than today. An overnight low of -9 will refreeze today's suncrust. The alpine high will hit -4. Ridge winds will be light, and gusting to moderate from the west. Freezing level is expected to be 1700m. No precip is expected.

Avalanche Summary

A few isolated loose wet avalanches were noted today. All were about sz1.

Snowpack Summary

Valley bottom up to 2100 is still suffering from the Feb crust. There is 5-10cm's on top of it which is making upward travel easier . On the way down , the crust is breakable in many places and tricky skiing. At treeline the crust almost instantly turns to hard slab. These slabs were formed by a wind event last week. The density of these slabs ranges from very hard (hard to get an edge) to breakable. Beneath these new slabs are the older Jan 31st slabs, down 30-50cm's. The alpine has had considerable wind over the past week. In places the underlying layers have been blown clean. The windloading pattern is very easy to see right now. At all elevations, the sun had a huge impact today. A sun crust will be present on all south aspects and its thought to extend up to 2500m.

Problems

Persistent Slabs

The post Jan 31st slabs have been reclassified as a persistent problem. Steep areas below ridge crests are a likely place to encounter this issue. The slabs are generally thick, and hard. Its unlikely to hit one, but it will be big if it happens.

Choose well supported terrain without convexities.>Watch for areas of hard wind slab in steep alpine features.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

These slabs area relatively easy to spot and predict. Open slopes at treeline is where these slabs start to appear.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.>Make observations and assess conditions continually as you travel.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

As our snowpack slowly grows it becomes easy to forget about the bottom layers. Remember that the bottom is still weak in many places and requires a deep snowpack to safely bridge the bottom layers.

Be aware of thin areas that may propogate to deeper instabilites.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 5

Valid until: Feb 24th, 2015 2:00PM