Avalanche Forecast

Issued: Feb 8th, 2015 7:07AM

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

Alberta Parks matt.mueller, Alberta Parks

We are barely out of the natural cycle. That puts us in the human triggering phase of the cycle. Be aware of your surroundings and keep tabs on the snow as you travel through the terrain. We are expecting a sudden temperature spike tomorrow.

Summary

Confidence

Good

Weather Forecast

Another warm day is coming down the pipe. We are expecting a rapid warming trend late tomorrow morning.  Freezing levels will rise from 1400m to 2200m over a few hours! There may also be some sun poking through the clouds at the same time. Watch for the quick temperature rise! Aside from the temps, there will be some flurries, but no significant accumulation. The ridge top winds will range from 15-30 km/hr.

Avalanche Summary

No new avalanches were confirmed today, however there were too many fresh crowns to rule out the end of the natural cycle. Public photo submissions yesterday informed us of significant avalanches at Burstall Pass. A sz2,5 was remotely triggered near a windloaded alpine feature. In Hero's Bowl, some paths went to valley bottom.

Snowpack Summary

The recent storm snow has settled at all elevations. Below treeline the new snow is a heavy, dense, 30cm thick layer that is sitting on a relatively weak mid pack. There was widespread whumphing in many open, untouched areas today. Shaded areas were slightly drier, but still dense. The moist snow didn't disappear until 2050m. 2050m to treeline still had a distinct slab, but the stronger midpack seemed to handle the load a little bit better. Having said that, whumphing was still observed with very isolated cracking. The Jan31st was down 40 on a west aspect and up to 70cm's on an East(lee)Upper alpine and alpine terrain had obvious wind loading. The certainty of the windslabs prevented us from directly assessing their reactivity, but it is fair to say human triggering is almost certain right now. The load of this recent storm is significant, the snowpack will takes its time adjusting.

Problems

Storm Slabs

An icon showing Storm Slabs
Typically storm slabs bond fairly quick. These slabs are expected to take a bit more time due to the heavy nature of the new snow and the underlying surfaces. Below treeline, these slabs are more of a settlement slab concern instead of windslab.
Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 4

Wind Slabs

An icon showing Wind Slabs
The older slabs are still there and suspect. Again, the poor bond to the Jan 31st crust/surface hoar is to blame. Steep areas are concerning right now.
Avoid cross loaded slopes at or above treeline.>Choose well supported terrain without convexities.>Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
More of a concern with large triggers. Avalanches, cornices, rockfall are all potential triggers. Avoid exposure to  big terrain until this layer adjusts to the new load.
Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Be aware of thin areas that may propogate to deeper instabilites.>Pay attention to overhead hazards like cornices.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

3 - 6

Valid until: Feb 9th, 2015 2:00PM

Login