Avalanche Forecast

Issued: Feb 20th, 2016 7:25AM

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

matt.mueller, Alberta Parks

Kananaskis.

The forecast calls for cooler temps but it is now mid February and we have a complex snowpack with persistent weak layers, recently buried melt-freeze and solar crusts with big cornices looming. When the sun pops out, the solar heating is significant

Summary

Confidence

High

Weather Forecast

Sunday should bring cooler temperatures - freeze levels at valley bottom. Cloudy in the morning and the sun might pop out in the afternoon. Winds will be out of the west 45km/h at treeline. No precipitation anticipated.

Avalanche Summary

To the eastern edge of our forecast region, a fresh 1.5 and a size 2.0 were observed on solar aspects of Mt. Nestor in the alpine. These slabs are likely failing as a result of a combination of wind loaded slabs on top of sun crusts with a bit of local solar warming.

Snowpack Summary

The snowpack is beginning to take on characteristics of late winter/early spring. The january 6th facets are buried about 80cm deep but are giving no results to spotty sudden collapses in isolated locations above treeline and alpine. There are also several melt-freeze & sun crusts from February 11th (40-50 cm) and February19th buried about 10-15cm. A complex array of storm slabs, wind slabs, cornices and deeply buried persistent weak layers in the mid to upper snowpack coupled with variable and difficult to predict results in snowpack tests. Snowpack areas that are thin (less than 100cm) are weak and facetted.

Problems

Storm Slabs

Storm slabs from last weeks light incremental snowfalls have piled up into some significant storm slabs. Watch for these slabs as you get above 2100 meters, especially on solar aspects where these slabs rest atop crusted interfaces.

Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Wind Slabs

The last 10 day has seen no shortage of wind in the land of "K". Pay particular attention to cross wind affected areas and wind loaded start zones at treeline and above. Be extremely careful if crusts are detected beneath these wind slabs.

Caution in lee and cross-loaded terrain near ridge crests.>Dig down to find and test weak layers before committing to a line.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Persistent Slabs

As previously mentioned, snowpack tests are showing less alarming results on this layer but strong caution must taken in shallow snowpack features at treeline and especially in the alpine where the winds have had greater effect on distribution.

Avoid steep slopes below cornices.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Valid until: Feb 21st, 2016 2:00PM