What are some of the recent analogs for a NW onshore pattern progressing into an arctic blast. I know it happens but i'm more used to a ridge retrograding and allowing the cold air to come in behind it.

You'll likely have to wait until it's already happening for the hammer to drop...

we're getting there, also we're not there

we have a guy for everything

There are encouraging signs of another wave break around Christmas. It just might take a little while (closer to new years) to get a good push of continental arctic air.