The best pinball show in the Pacific Northwest, NorthWest pinball show (http://www.nwpinballshow.com/) is first weekend of June next year. Hundreds of pinball machines to play, extremely competitive tournament, and a short nice drive down from Vancouver.

You should visit Seattle anyhow, the pinball scene is fantastic and there's a tournament almost every day of the week (check out https://www.skill-shot.com/ for more details on locations and tournament calendar). This thread, https://pinside.com/pinball/forum/topic/seattle-bound, has a lot of good info in it also.

And while you are at it, don't shy away from visiting Portland. It's the only city with slightly higher number of pinball machines to play per capita than Seattle