Avalanche Forecast

Issued: Apr 27th, 2014 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Still some good skiing found on sheltered North aspects at higher elevations. However, watch for rapid rises in avalanche danger related to solar radiation and warm temperatures. Start early and finish early.

Summary

Confidence

Good

Weather Forecast

Wednesday should be mostly sunny with NW winds gusting to 55 km/h. Alpine temperatures should reach -3 degrees with freezing levels near 1700m. The rest of the week will see a warming in temperatures with freezing levels near 3100m by Thursday.

Avalanche Summary

Nothing new observed today, but a size 3.0 slab avalanche occurred on Commonwealth Ridge sometime Saturday. This was a full-depth avalanche on a SE aspect that ran full path and destroyed mature timber.

Snowpack Summary

Between 2 and 8cm of new snow overnight depending on aspect and elevation. This overlies a melt freeze crust on all aspects at all elevations except for North aspects above 2400m. Isolated thin wind slabs are found at ridge-crest in immediate lee slopes, but generally don't seem to be reactive to ski cutting. The basal facet and depth hoar remain a concern during times of intense heating and/or solar radiation. Where cornices exist they are large and sagging.

Problems

Deep Persistent Slabs

The basal facets are producing large slab avalanches that are failing on the basal facets.

Make your travel plans to take advantage of overnight freezing.>Pay attention to overhead hazards like cornices.>Be aware of thin areas that may propogate to deeper instabilites.>Ski crampons make travel easier and safer on frozen surface conditions>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 6

Loose Wet

Timing is everything at this time of year. Solar radiation is intense and can lead to rapid destabilization of the snowpack. Air temperatures are also a concern as the snowpack grows isothermal at lower elevations later in the day.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Make your travel plans to take advantage of overnight freezing.>Start and finish early before the surface crusts melt.>

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 28th, 2014 2:00PM