Hello!
Firstly, thank you very much for sharing, I'd love to see any moths you have from your side of the pond 🦋
Secondly, the US is a big 'ole place, and theres lots of species I've never seen before (or heard off before). But I like a challenge!!
I tried a google image search which was hit and miss, but on the 3rd attempt I managed to find something similar - it might be a Girlfriend Underwing? - Catocala amica
source - https://www.butterfliesandmoths.org/species/Catocala-amica
second source - https://en.wikipedia.org/wiki/Catocala_amica
There may be similar species, but this is a good start, it does appear to have bright yellow underwings, have you seen your moth move? The yellow underwings would be visible when it flies
No, it was firmly staying on the siding, but I think you did find it! What a cool name, 'Girlfriend Underwing'! Thank you for looking for me! I've seen a few moths but never been able to get photos. My camera is SO slow, but this one wasn't moving, so I got lucky.