My AST 2 class observed a size 3 avalanche off of the 2640m western sub peak of Mount Chester today, Sunday. The windslab looked to be triggered by a cornice collapse in the last 24 hours. The crown ran from approximately 2120 metres on the peak's NNW ridge wrapping around into the peak's northern flank and gulley and propagating across 800 metres to a high point of 2320 metres. In places the crown looked to be 2 metres and the debris ran full path.

We had several moderate to hard sudden planar shears on the Jan 6 and Dec 15 layers down 70 to 100 cms on a 33 degree northern slope at about 2200 metres. On the same slope we had a rustchblock 3 sudden planar failure on the Dec 15th that swept the loader, me, off of the block.

Our tests and observations convinced us of the high danger at and above tree line today and we stayed out of avalanche terrain.

My -28 C morning warmed to -4 on high and that was a pleasant change. Thank you Mr Inversion

Happy trails,

Barry Blanchard
Mountain Guide
Yamnuska Mountain Adventures
www.yamnuska.com