Unlucky or Poor Decisions?

Today Stu and I triggered a slide on the West Face of Aonach Mor. Why? Here are my thoughts

Last night we looked at the SAIS forcast

This showed that the W/SW aspects were the least likely to be affected with a forecast of LOW

We chose to go to The West Face of Aonach Mor and climb a route called Golden Oldy (II). This would have put us on the lower risk side of the mountain. Winds were forecast as low speed Easterly and picking up during the afternoon. This of course would move snow over to the west during the day but hopefully later in the day.

Our plan was simple. Skin up to the summit of Anoach Mor, ditch skis, either down climb Downhill Gully (1) or walk round to the Aonach Mor/Aonach Beag beleach and approach the routes from there. These would mean we did not have to carry skis and they would be at the top for our descent.

During our planning phase we had considered the weather, the party (2 competent mountaineers) and the terrain

During the travel phase we had maybe not picked up as much information about the snow as we could have, maybe because we were on skis and this does reduce the feedback from your feet. Also we skinned up a piste so this again has impacted on the snow feel.

Our first key decision point was the summit of Aonach Mor at 1221m. We were aware of the slightly stronger than forecast Easterly winds and the lack of visibility at the top meant we chose to head to the bealach as we could not see the top of Downhill Gully and we were concerned about the snow accumulations in the top of the gully

At the bealach we turned west and started to head down into the Alt Daim. I stopped as suddenly I felt something in the snow that I didn't like. Stu took one more step (with a planted axe) and a crack propagated around 15m from his foot and the whole area slid away below him (he was fine). The depth of the slide was only 3-4 inches but at 10-15m wide this could have easily taken one of us with it. It went about 60m before going out of sight.

We needed no discussion or debate and walked back to the bealach and back to our skis. The day got worse when I broke the top buckle on my ski boot which made the descent interesting. 

The slide has been reported via the SAIS website and I will be thinking over the next few days whether there was a flaw in our decision making or we were just unlucky.

For those that don't know, here is the latest aid to Avalanche Awareness