Avalanche Forecast

Issued: Feb 4th, 2017 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

Times are changing.  New snow and winds are causing avalanche danger to increase.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Sunday

Weather Forecast

An additional 20cm of snow is forecast to fall over the next 24hrs with winds beginning to increase into the moderate range.  Winds will continue to be cold.

Avalanche Summary

A few loose dry avalanches up to sz 1 were observed out of steeper terrain in the alpine. 

Snowpack Summary

20cm of recent storm snow (2150m) sits on top of a widespread hard wind slab from the Jan 29th wind event. The thickness of this slab varies between 10 & 30cm. A touchy facet layer sits below the hard wind slab. The midpack is consistently weak. The Nov 12 basal crust is still intact in some areas with depth hoar and facets below. The storm came in with very little wind. At the moment its thought there are isolated alpine storm slabs in immediate lee areas

Problems

Storm Slabs

An icon showing Storm Slabs
Recent new snow on Saturday and into Sunday combined with moderate westerly winds will build new storm slabs in alpine terrain.
Avoid freshly wind loaded features.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Loose Dry

An icon showing Loose Dry
Loose dry slides may trigger storm slabs on underlying slopes.
Be cautious of sluffing in steep terrain.Sluffs may trigger deeper instabilities.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Very Likely

Expected Size

1 - 1

Persistent Slabs

An icon showing Persistent Slabs
Triggering of these slabs from a thin weak area may cause an avalanche that involves the deeper layers and the entire snowpack. 
Minimize exposure during periods of heavy loading from new snow and wind.Be aware of thin areas that may propogate to deeper instabilites.Use caution on open slopes and convex rolls

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Feb 5th, 2017 2:00PM