It's Not Quite Dead Yet

We went to the Skyland area to check on the persistent slab problem.

• We saw a recent, large, natural hard slab avalanche. It failed on a convex break over and we could see rocky outcrops in the bed surface. We couldn't see how far it ran because the track was behind a ridge, but the crown was about 3 feet deep and 200 feet wide. The crown looked very crisp and there was no new or drifted snow on the bed surface. We debated for a long time, while staring through binoculars, whether it ran over the weekend, yesterday, or even today during the intense sun.
• We tested the late January weak layer in a snow pit at 6400 feet on a north aspect where there was no melt-freeze crust at the surface. We found facets sandwiched between 2 crusts over 4 feet deep under a hard slab. Our test results indicated that, if you found a shallower area, or a trigger point where you could collapse the weak layer, it could still propagate across the slope. We tracked this layer by probing and found it buried up to 6+ feet deep on easterly slopes and 4-5 feet deep on westerly slopes.
• We also tracked the melt-freeze crust that began forming during last week's warm-up. The crust was thinner on shady slopes and disappeared around 6300 feet on those aspects. The crust is thick and supportable to at least 7200 feet on southerly aspects. We also found a couple inches of cold, dry snow above the crust on shady slopes. On slopes baking in the sun, we saw lots of small roller balls as the new snow thawed and tumbled down the hill in chunks.