I have been heli-skiing in the Selkirks and Monashee ranges around Revelstoke for the last 4 days. Our main concern has been two surface hoar layers that are relatively close to each other and currently found as deep as 50cm from the surface in the Monashees and a bit shallower in the Selkirks . While we have had a lot of issues this season already with buried surface hoar instabilities, this layer combo seems to be the most reactive and troublesome so far as 1) it is prevalent all the way into the alpine 2) requires very little trigger (we triggered a size 2.5 from 200 meters away by landing with a (small) Bell 407 helicopter on a peak above a southerly aspect at 2600 meters) which in turn triggered additional smaller avalanches sympathetically and 3) shows enormous potential for propagation (meaning the fracture travels a long way – we have heard of 500 meter fracture lines in the Purcells for example) which makes for the potential of catastrophic slides.
At the same time, we found the northern aspect particularly touchy in the last few days. Yesterday, with the onset of the nice weather, we have lost a lot of the non-northern aspects to the solar radiation (i.e. sun crust by now) which will draw a lot of backcountry users to the Northern aspects during the coming weekend. Also, the current poor snow stability is not likely to go away soon. In the 14 years that I have been heli-skiing around Revelstoke, I have rarely seen such a red (=no go) run list and so much large scale natural or low trigger avalanche activity even on low angle ski runs.
Stay safe out there……
Jorg Wilz
Mountain Guide (ACMG / IFMGA)
1-800 506-7177 or (001) (403) 678-2717