Avalanche Forecast

Issued: Apr 15th, 2017 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

Temps are forecast to increase tomorrow and we may see some sun come out.  Watch for the solar radiation de-stabilizing slopes on solar aspects throughout the day.

Summary

Confidence

High -

Weather Forecast

Winds are forecast to begin to decrease overnight and temperatures begin to climb slightly.  Freezing level is forecast to only reach 2100m but more sun will be likely Sunday so we may see solar radiation begin to destabilize the slopes on solar aspects.

Avalanche Summary

No new avalanche activity was observed on Saturday with field teams in the tent ridge area.  Conditions were obscured in most areas with poor light.

Snowpack Summary

A few cm of snow overnight and throughout the day on Saturday.  This came with strong winds and cool temps and prompted a return to winter.  This snow is overlying widespread crusts on on aspects up to 2200m and on solar aspects up to 2700m.  New windslabs are being encountered in Alpine terrain or N through east aspects as a result of strong winds over the past few days.  Solar aspects have also been blow down to the previous crust in alpine terrain.  100-140cm of settled snow is overlying the weak basal facets.  Moderate to hard sheers persist in these basal facets and are sudden collapse in nature.  There is no hit of the snowpack starting to go isothermal in most areas. 

Problems

Wind Slabs

An icon showing Wind Slabs
Windslabs are forming on lee aspects (N and E) in alpine areas as a result of strong SW winds on friday and saturday.
Avoid freshly wind loaded features.Assess start zones carefully and use safe travel techniques.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
We are not entirely free from this layer yet. It is still down there and more suspect in thin areas, cold areas that haven't seen a warming cycle and large terrain that hasn't avalanched yet.
Pay attention to overhead hazards like cornices which could easily trigger deep slabs.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 16th, 2017 2:00PM