Making Decisions with Wind Slabs

We toured up the west ridge of Mt Edwards to investigate recently developed wind and storm slabs.

• On the way up the ridge our main concern was the wind slab problem. The wind during the last storm had come from variable directions leaving wind slabs on different aspects of the ridge. We noticed cracks up to a 6 feet long in some drifts. We dug a pit in one of these slabs on a mid elevation, northwest aspect and got a propagating result in the wind slab. Up higher there were cornices building and we were able to knock off some large blocks, however it did not entrain any snow on the slope below them.
• The day started out with calm winds and a high cloud ceiling. The winds picked up as a storm front moved in around noon, winds began gusting up to moderate with some ligh blowing snow at ridge tops.
• We found the freezing rain crust from New Years at mid to upper elevations. The crust was more prounounced the higher we went. We felt some localized collapses that might have been this crust breaking or it could have just been buried logs in the snowpack.
• At low elevations, below 4200', there was a rain crust from yesterday morning.
• On open south facing aspects at low elevations we noted a sun crust from yesterday afternoon.
• We did not notice any recent avalanche activity in the surrounding area during the morning while the visibility was good.
• On the way down we did see rollerballs just starting to form on a south facing aspect at mid and lower elevations.

In order to manage the wind slab problem we decided to ski wind sheltered slopes where we felt ok skiing steeper terrain.