There was not one thunderstorm in the years I lived in the PNW or the years I lived in Austin TX, it is more complicated than how far north you are. There was a very good thunderstorm during my vacation in Alaska a few years ago but I have no idea how common they are there, no one remarked on it being a rare occurrence, just that it was a good storm.
Very rare in the PNW (or at least Washington) and Alaska. Thankful for that as the chances of a fire starting from them seems high. Last summer we only had one lighting "storm" which had a total two lighting strikes and one of them started a fire.
I don't exactly have solid data on it, but from what I've seen the big thunderstorms of Dallas don't often get further South than like Waco. Even Dallas seems to miss a lot of the big storm fronts or only get hit by the tail of them.
