Above the Crust

We traveled up to 7000' above Marion Lake on Peak 7798 to monitor the persistent slab problem.

• We watched a small sluff run naturally from a very steep rocky chute on a sunny slope at noon. We saw many new small and medium sized rollerballs on southerly slopes by the afternoon. We avoided skiing very steep sunny slopes not only because we felt we could trigger a small loose wet avalanche, but because the snow surface there was wet and punchy (wet and dense down about an inch over dry snow) and the riding would be terrible. You could wrench your knee.
• We saw no signs of storm slab, wind slab, or persistent slab avalanches having run during the last loading event.
• We found that pesky crust up to 6300' on all aspects. It was very hard (P to K) up to 5800', and thinner and softer (1F to 4F) from 5900' to 6300'. We found 1 to 3" of newer, low density snow on top of the crust that is starting to facet. We found 1-4mm surface hoar on top of that up to 6500' on E-N-W aspects on steep slopes and in sheltered areas.
• We dug 2 pits at middle and upper elevations to try and test the buried weak layers. The snowpack in both locations was strong and we had no propagating results.
• Warm, sunny day! Air temp at 7000' at 2pm was 36F.
• We had ruled out riding convex slopes and steep, rocky terrain with variable snow cover to avoid the high consequences of triggering the persistent slab problem. We skied planar and concave, shady slopes up to 40 degrees down to the lake with no problems to worry about.
• Below the lake we followed the bobsled track that used to be the summer trail to avoid hurting ourselves on the breakable crust.