Avalanche Forecast

Issued: Feb 3rd, 2015 7:06AM

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

Alberta Parks matt.mueller, Alberta Parks

Hazard ratings may change at a moment's notice if the winds pick up. Consider alpine and treeline ratings to be at their upper limits right now.  Choosing a safe line still requires some assessment and monitoring of changing conditions.

Summary

Confidence

Good

Weather Forecast

The flurries that we experienced today are expected to come to an end overnight. There may be a few more cm's accumulation, but nothing too significant. Alpine and ridge top winds will pick up tonight, topping out at 30-50km/hr from the SW. The alpine temperatures will be around -8 as a high.

Avalanche Summary

No avalanches were seen today

Snowpack Summary

15-20cm's of new, low density snow at treeline. The underlying crust is still apparent at all elevations. In most places the crust is breakable despite the new snow. Treeline and below has no significant avalanche concerns at the moment. The warm spell locked the snow in place with the crust. At treeline the picture starts to change. The treeline/alpine transition is a bit more complex. The moderate winds have created soft slabs on all lee aspects. So far the slabs don't extend too far below ridge lines and open areas at treeline where the winds could penetrate the trees. The bond with the underlying layers seems to be hit and miss. Any slab that is on the crust seems to be bonding reasonably well and anything on an old hardslab is slower to come around. Snow depth at treeline averages 160cm's.

Problems

Wind Slabs

An icon showing Wind Slabs
These new slabs could become concerning as the winds build. The "touchiness" of these slabs will rise very quickly if the winds pick up, or change direction. Start to look for them when approaching open areas at treeline.
Avoid freshly wind loaded features.>Make observations and assess conditions continually as you travel.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Eastern parts of the region have seen recent activity with this layer. The upper slabs have triggered this weak layer initiating large avalanches.  Despite the lack of activity in the western areas, the problem and concern is still there.
Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Carefully evaluate and use caution around thin snowpack areas.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Feb 4th, 2015 2:00PM