Potential riming was in the forecast, and my first clue was sitting at home when I noticed some of the upper elevation wind stations stopped working - speed and/or direction - combined with 100% relative humidity. This often can mean they've rimed up.

Went to check it out - definitely riming. The rime feathers grow into the wind, so the wind was coming from left to right here.

Rime crusts (compared to rain crusts) are:

The rime crust is actually quite thin in this area, especially compared to the build up on the trees and poles. (In these pictures there is still additional snow sticking to the crust, so the crust is way thinner than it looks) A concern for the future is that the crust is covering the weak facets beneath on the shady slopes, and will help protect and preserve the facets from heat and wind. While quite thin, these crusts can still be significantly durable. Today's riming event was also very elevation dependent - above about 9,500' in some places, as low as 8,500' in other places. Checking out a few lower elevation sites on my way back down the canyon, the surface snow certainly has warmed. However, the weak facets layer is so deep on the shady slopes, that there are still plenty of facets beneath the now stronger surface layers.