Thanks, Robin, for such detailed and helpful information! I really appreciate the time you put into the ID!

from Moths page to new species page which describes the adult, and lists features that distinguish it from similar species

Cucullia strigata to me. The closest other candidate is probably C. albida, whose forewing has less conspicuous reniform and orbicular spots, and a slightly different pattern of streaking along the inner margin, and its hindwing has a more contrasting mix of dark gray and white - judging from these two CBIF images.
I looked through all the images by Bruce Walsh and CBIF and didn't see a closer match (most lack pale spots along the outer margin of the forewing).
One of the synonyms of C. strigata is ketchikana, so I'm assuming it occurs north to at least the Alaskan panhandle, and south to Oregon (it's listed as Rancora strigata at Oregon State U. but is missing from the list of California moths)