PWL: Rain Crust Observations

Wanted to post this thread to start a discussion regarding observations of rain crusts.

After a BC session around Crystal on Saturday (12/, signs of this PWL were very apparent... Looks as though we may be setting up for a rather dangerous avalanche season with such an early PWL...

Curious to hear about other's field observations.

I'm curious to know the thickness.

I'm curious to know the thickness.

I observed the same thing as Link...
I did not get down and measure but I noticed that it was a veneer large grain ice layer probably 3-4 mm thick and crumbled with any aggressive finger swipe.
I know that does not conform to the agreed standard of data input.
So call it Med/Hard surface; Granular

I have seen at least two of these similar layers on Hasty pits due to the warm ups and then new snow or transport. Some of the rain has been limited at higher elevation (5500ft and above) and the pack did not get quite the soaking as the lower elevations.
IMO the recent warming Sunday 12/9 will do the same thing since it was followed by colder temps. I need to follow up to see the results, but my gut tells me that the bridge will be weak in that one too.

Is this the rather thick crust from the significant rain event on or around Nov 23rd, or a more superficial layer?

Is this the rather thick crust from the significant rain event on or around Nov 23rd, or a more superficial layer?

I think its the one from around December 4-5. We were able to find it at Crustal last Friday underneath the most recent storm snow. It wasn't there on 12/2 or we didn't notice it in the fresh stuff we were skinning up. On 12/7 it seemed like it was holding okay to the rain crust but that's just based on some crude hand shear tests. The snow wasn't real consolidated so it wasn't the best observation setting.

Like Chuck's info...I did not dig that far down, so I am referring to the upper layers that have been effected by the recent temp fluctuations and loadings sandwiched between them.